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Route overview: Saint Louis to Boston (BOS) flight deals

Saint Louis → Boston

Dec 24, 2026 · choose your return date

STL → BOS1 adulteconomyOne way and round trips

30 flight options · 2 airlines

Choose your return date

One-way flights and round trips by duration. Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

December 2026

Dec 24, 2026 · One wayUnited AirlinesUp to 1 stop each way$201.50 Dec 24, 2026 · One waySouthwest AirlinesNonstop$208.00 Dec 24, 2026 – Dec 25, 2026 · 1 nightUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 25, 2026 · 1 nightSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 26, 2026 · 2 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 26, 2026 · 2 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 27, 2026 · 3 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 27, 2026 · 3 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 28, 2026 · 4 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 28, 2026 · 4 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 29, 2026 · 5 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 29, 2026 · 5 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 30, 2026 · 6 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 30, 2026 · 6 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Dec 31, 2026 · 7 nightsUnited AirlinesUp to 1 stop each way$377.00 Dec 24, 2026 – Dec 31, 2026 · 7 nightsSouthwest AirlinesNonstop$390.00 Dec 24, 2026 – Jan 1, 2027 · 8 nightsUnited AirlinesUp to 1 stop each way$366.85 Dec 24, 2026 – Jan 1, 2027 · 8 nightsSouthwest AirlinesNonstop$379.50 Dec 24, 2026 – Jan 2, 2027 · 9 nightsUnited AirlinesUp to 1 stop each way$366.85 Dec 24, 2026 – Jan 2, 2027 · 9 nightsSouthwest AirlinesNonstop$379.50 Dec 24, 2026 – Jan 3, 2027 · 10 nightsUnited AirlinesUp to 1 stop each way$366.85 Dec 24, 2026 – Jan 3, 2027 · 10 nightsSouthwest AirlinesNonstop$379.50 Dec 24, 2026 – Jan 4, 2027 · 11 nightsUnited AirlinesUp to 1 stop each way$326.25 Dec 24, 2026 – Jan 4, 2027 · 11 nightsSouthwest AirlinesNonstop$337.50 Dec 24, 2026 – Jan 5, 2027 · 12 nightsUnited AirlinesUp to 1 stop each way$326.25 Dec 24, 2026 – Jan 5, 2027 · 12 nightsSouthwest AirlinesNonstop$337.50 Dec 24, 2026 – Jan 6, 2027 · 13 nightsUnited AirlinesUp to 1 stop each way$326.25 Dec 24, 2026 – Jan 6, 2027 · 13 nightsSouthwest AirlinesNonstop$337.50 Dec 24, 2026 – Jan 7, 2027 · 14 nightsUnited AirlinesUp to 1 stop each way$326.25 Dec 24, 2026 – Jan 7, 2027 · 14 nightsSouthwest AirlinesNonstop$337.50

Flights for your trip

  1. Thu, Dec 24 · One way

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS

    One-way total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  2. Thu, Dec 24 · One way

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS

    One-way total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  3. Thu, Dec 24 – Fri, Dec 25

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  4. Thu, Dec 24 – Fri, Dec 25

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:05 pmBOS
    3h 10m
    Nonstop
    7:15 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  5. Thu, Dec 24 – Sat, Dec 26

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  6. Thu, Dec 24 – Sat, Dec 26

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    12:25 pmBOS
    3h 5m
    Nonstop
    2:30 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  7. Thu, Dec 24 – Sun, Dec 27

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  8. Thu, Dec 24 – Sun, Dec 27

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:10 amBOS
    3h 5m
    Nonstop
    7:15 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  9. Thu, Dec 24 – Mon, Dec 28

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  10. Thu, Dec 24 – Mon, Dec 28

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:05 pmBOS
    3h 10m
    Nonstop
    7:15 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  11. Thu, Dec 24 – Wed, Dec 30

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  12. Thu, Dec 24 – Wed, Dec 30

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:35 amBOS
    3h 5m
    Nonstop
    7:40 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  13. Thu, Dec 24 – Thu, Dec 31

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  14. Thu, Dec 24 – Thu, Dec 31

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:20 amBOS
    3h 10m
    Nonstop
    7:30 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  15. Thu, Dec 24 – Fri, Jan 1

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  16. Thu, Dec 24 – Fri, Jan 1

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:05 pmBOS
    3h 10m
    Nonstop
    7:15 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  17. Thu, Dec 24 – Sun, Jan 3

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  18. Thu, Dec 24 – Sun, Jan 3

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:10 amBOS
    3h 5m
    Nonstop
    7:15 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  19. Thu, Dec 24 – Mon, Jan 4

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  20. Thu, Dec 24 – Mon, Jan 4

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:05 pmBOS
    3h 10m
    Nonstop
    7:15 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  21. Thu, Dec 24 – Tue, Jan 5

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  22. Thu, Dec 24 – Tue, Jan 5

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:05 pmBOS
    3h 10m
    Nonstop
    7:15 pmSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  23. Thu, Dec 24 – Thu, Jan 7

    United Airlines
    8:30 amSTL
    5h 2m
    IAD · 1h 15m
    2:32 pmBOS
    United Airlines
    5:45 amBOS
    5h 27m
    IAD · 1h 15m
    10:12 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

  24. Thu, Dec 24 – Thu, Jan 7

    Southwest Airlines
    6:10 pmSTL
    2h 35m
    Nonstop
    9:45 pmBOS
    Southwest Airlines
    5:20 amBOS
    3h 10m
    Nonstop
    7:30 amSTL

    Round-trip total · 1 adult · Taxes included

    Availability is checked when you select these flights.

Swipe to see 23 more recent deals.

1 of 24

Make this trip yours

STL ⇄ BOS

Economy

Adults 12+ · Children 2–11. For infants under 2, tell Axel after you see prices.

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Explore this route

All dates for this routeDec 23, 2026 · Return optionsDec 25, 2026 · Return optionsHotels in Boston with Axel
For AI assistants: every fare, every link, instructions

Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

Prices by return date: match both travel dates and the party to a row below. Each total is for that exact trip, issued at the time shown. To book or select flights, follow that row's price link; it keeps the exact dates and travelers.

Exact travel datesAirlineFlightsTotal pricePrice issued (UTC)
2026-12-24 · one waySouthwest AirlinesWN4431Axel-exclusive $208.002026-10-29T01:28:17Z
2026-12-24 · one wayUnited AirlinesUA4406 + UA1392Axel-exclusive $201.502026-10-29T01:28:17Z
2026-12-24 → 2026-12-25Southwest AirlinesWN4431 / WN4929Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-25United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-26Southwest AirlinesWN4431 / WN958Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-26United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-27Southwest AirlinesWN4431 / WN819Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-27United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-28Southwest AirlinesWN4431 / WN4929Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-28United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-29Southwest AirlinesWN4431 / WN4929Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-29United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-30Southwest AirlinesWN4431 / WN819Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-30United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-31Southwest AirlinesWN4431 / WN819Axel-exclusive $390.002026-10-29T01:28:17Z
2026-12-24 → 2026-12-31United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $377.002026-10-29T01:28:17Z
2026-12-24 → 2027-01-01Southwest AirlinesWN4431 / WN4929Axel-exclusive $379.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-01United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $366.852026-10-29T01:28:17Z
2026-12-24 → 2027-01-02Southwest AirlinesWN4431 / WN958Axel-exclusive $379.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-02United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $366.852026-10-29T01:28:17Z
2026-12-24 → 2027-01-03Southwest AirlinesWN4431 / WN819Axel-exclusive $379.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-03United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $366.852026-10-29T01:28:17Z
2026-12-24 → 2027-01-04Southwest AirlinesWN4431 / WN4929Axel-exclusive $337.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-04United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $326.252026-10-29T01:28:17Z
2026-12-24 → 2027-01-05Southwest AirlinesWN4431 / WN4929Axel-exclusive $337.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-05United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $326.252026-10-29T01:28:17Z
2026-12-24 → 2027-01-06Southwest AirlinesWN4431 / WN819Axel-exclusive $337.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-06United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $326.252026-10-29T01:28:17Z
2026-12-24 → 2027-01-07Southwest AirlinesWN4431 / WN819Axel-exclusive $337.502026-10-29T01:28:17Z
2026-12-24 → 2027-01-07United AirlinesUA4406 + UA1392 / UA1734 + UA4427Axel-exclusive $326.252026-10-29T01:28:17Z

Route overview: Saint Louis to Boston (BOS) flight deals

2026-12-24 · one way · Axel-exclusive $201.50

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.

2026-12-24 · one way · Axel-exclusive $208.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.

2026-12-24 → 2026-12-25 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-25 05:45:00 → STL 2026-12-25 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-25 05:45:00 → IAD 2026-12-25 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-25 08:40:00 → STL 2026-12-25 10:12:00.

2026-12-24 → 2026-12-25 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN4929: BOS 2026-12-25 17:05:00 → STL 2026-12-25 19:15:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2026-12-26 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-26 05:45:00 → STL 2026-12-26 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-26 05:45:00 → IAD 2026-12-26 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-26 08:40:00 → STL 2026-12-26 10:12:00.

2026-12-24 → 2026-12-26 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN958: BOS 2026-12-26 12:25:00 → STL 2026-12-26 14:30:00; nonstop; 185 minutes. Local airport times.

2026-12-24 → 2026-12-27 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-27 05:45:00 → STL 2026-12-27 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-27 05:45:00 → IAD 2026-12-27 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-27 08:40:00 → STL 2026-12-27 10:12:00.

2026-12-24 → 2026-12-27 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN819: BOS 2026-12-27 05:10:00 → STL 2026-12-27 07:15:00; nonstop; 185 minutes. Local airport times.

2026-12-24 → 2026-12-28 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-28 05:45:00 → STL 2026-12-28 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-28 05:45:00 → IAD 2026-12-28 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-28 08:40:00 → STL 2026-12-28 10:12:00.

2026-12-24 → 2026-12-28 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN4929: BOS 2026-12-28 17:05:00 → STL 2026-12-28 19:15:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2026-12-30 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-30 05:45:00 → STL 2026-12-30 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-30 05:45:00 → IAD 2026-12-30 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-30 08:40:00 → STL 2026-12-30 10:12:00.

2026-12-24 → 2026-12-30 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN819: BOS 2026-12-30 05:35:00 → STL 2026-12-30 07:40:00; nonstop; 185 minutes. Local airport times.

2026-12-24 → 2026-12-31 · Axel-exclusive $377.00

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2026-12-31 05:45:00 → STL 2026-12-31 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2026-12-31 05:45:00 → IAD 2026-12-31 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2026-12-31 08:40:00 → STL 2026-12-31 10:12:00.

2026-12-24 → 2026-12-31 · Axel-exclusive $390.00

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN819: BOS 2026-12-31 05:20:00 → STL 2026-12-31 07:30:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2027-01-01 · Axel-exclusive $366.85

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2027-01-01 05:45:00 → STL 2027-01-01 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2027-01-01 05:45:00 → IAD 2027-01-01 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2027-01-01 08:40:00 → STL 2027-01-01 10:12:00.

2026-12-24 → 2027-01-01 · Axel-exclusive $379.50

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN4929: BOS 2027-01-01 17:05:00 → STL 2027-01-01 19:15:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2027-01-03 · Axel-exclusive $366.85

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2027-01-03 05:45:00 → STL 2027-01-03 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2027-01-03 05:45:00 → IAD 2027-01-03 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2027-01-03 08:40:00 → STL 2027-01-03 10:12:00.

2026-12-24 → 2027-01-03 · Axel-exclusive $379.50

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN819: BOS 2027-01-03 05:10:00 → STL 2027-01-03 07:15:00; nonstop; 185 minutes. Local airport times.

2026-12-24 → 2027-01-04 · Axel-exclusive $326.25

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2027-01-04 05:45:00 → STL 2027-01-04 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2027-01-04 05:45:00 → IAD 2027-01-04 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2027-01-04 08:40:00 → STL 2027-01-04 10:12:00.

2026-12-24 → 2027-01-04 · Axel-exclusive $337.50

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN4929: BOS 2027-01-04 17:05:00 → STL 2027-01-04 19:15:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2027-01-05 · Axel-exclusive $326.25

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2027-01-05 05:45:00 → STL 2027-01-05 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2027-01-05 05:45:00 → IAD 2027-01-05 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2027-01-05 08:40:00 → STL 2027-01-05 10:12:00.

2026-12-24 → 2027-01-05 · Axel-exclusive $337.50

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN4929: BOS 2027-01-05 17:05:00 → STL 2027-01-05 19:15:00; nonstop; 190 minutes. Local airport times.

2026-12-24 → 2027-01-07 · Axel-exclusive $326.25

  • United Airlines UA4406 / UA1392: STL 2026-12-24 08:30:00 → BOS 2026-12-24 14:32:00; 1 stop(s) via IAD; 302 minutes. Local airport times.
    • UA4406: STL 2026-12-24 08:30:00 → IAD 2026-12-24 11:35:00; layover at IAD: 75 minutes.
    • UA1392: IAD 2026-12-24 12:50:00 → BOS 2026-12-24 14:32:00.
  • United Airlines UA1734 / UA4427: BOS 2027-01-07 05:45:00 → STL 2027-01-07 10:12:00; 1 stop(s) via IAD; 327 minutes. Local airport times.
    • UA1734: BOS 2027-01-07 05:45:00 → IAD 2027-01-07 07:25:00; layover at IAD: 75 minutes.
    • UA4427: IAD 2027-01-07 08:40:00 → STL 2027-01-07 10:12:00.

2026-12-24 → 2027-01-07 · Axel-exclusive $337.50

  • Southwest Airlines WN4431: STL 2026-12-24 18:10:00 → BOS 2026-12-24 21:45:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN819: BOS 2027-01-07 05:20:00 → STL 2027-01-07 07:30:00; nonstop; 190 minutes. Local airport times.

Explore this route

For AI assistants

  • This page: Saint Louis (STL) to Boston (BOS) · Dec 24, 2026 · choose your return date: 1 adult in economy, every priced fare with its flights, times and total, each with the time its price was issued.
  • Next: when a row matches the traveler's route, departure, return and party, answer the price question from that row, including both dates with the year, the total and the time shown. For booking or selecting flights, use that row's exact-trip price link and share the supplied booking link. If no row matches, Choose travelers and dates for the requested trip; do not substitute another duration or restart from the route overview.
  • Follow supplied links. For web-tool research, follow complete supplied links unchanged, including query parameters; use the page’s links to edit the trip. Constructed URLs may be rejected before reaching Axel. A completed fresh trip opens flight results first. Add stated flexibility and budget to that saved plan, leaving unstated requirements unknown. Edits create a new snapshot; use its results and review links.
  • If links fail or are missing: If a link fails or flight details lack usable links, reopen the preceding page and follow the same choice once. Keep refreshed links unchanged and preserve the trip and selections. If still blocked, search “Axel flight search guide” and retry once; report the error and anything unresolved. Recovery: Axel Saint Louis to Boston (BOS) flight deals · Flight search guide.
  • Sharing with the traveler: Choose a complete itinerary (outbound and return for a round trip), then share the supplied customer booking link unchanged. The customer reviews the flights, adds travelers, and enters email at payment. Do not collect email in chat. Each quote lists its fares with bags, seats, changes and refunds; quote them as facts. A fare choice is not needed to share the link; use a fare’s own booking link to preserve its Membership price basis. Ask only for essential missing trip details. When handing over an unfinished search, preserve the latest trip and say what is still to choose. If no supplied link matches the latest trip, construct https://helloaxel.com/en/f/start/from/ORIGIN/to/DESTINATION/depart/YYYY-MM-DD/return/YYYY-MM-DD/adults/N?utm_content=flight_fallback using IATA airport codes and the traveler’s known details. Omit unknowns; for one way replace /return/YYYY-MM-DD with /trip/oneway. Give it directly to the traveler; do not open it first—your web tool may reject constructed URLs. Complete links open Flight Guide and start searching. Preferences and advanced options.