Seattle (SEA) to Boston (BOS), May 9–18, 2027: from $545 round trip

Seattle (SEA) to Boston (BOS), May 9–18, 2027: from $545 round trip on Axel, checked Oct 29, 2026. Lowest published fare: $545 round trip, Axel-exclusive, Delta Air Lines, nonstop, May 9–18, 2027, 1 adult, economy, checked Oct 29, 2026. Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

See flights for these dates: each price link opens AI flight search for that row's exact dates and travelers. Select the complete itinerary there.

Route overview: Seattle to Boston (BOS) flight deals

2027-05-09 → 2027-05-18 · Axel-exclusive $545.00

• Delta Air Lines DL876: SEA 2027-05-09 15:55:00 → BOS 2027-05-10 00:12:00; nonstop; 317 minutes. Local airport times.
• Delta Air Lines DL332: BOS 2027-05-18 10:40:00 → SEA 2027-05-18 14:09:00; nonstop; 389 minutes. Local airport times.

2027-05-09 → 2027-05-18 · Axel-exclusive $545.00

• Delta Air Lines DL459: SEA 2027-05-09 07:15:00 → BOS 2027-05-09 15:43:00; nonstop; 328 minutes. Local airport times.
• Delta Air Lines DL332: BOS 2027-05-18 10:40:00 → SEA 2027-05-18 14:09:00; nonstop; 389 minutes. Local airport times.

Travelers: prices on this page are totals for 1 adult. For a different party, open this trip for 2 adults · 3 adults · 4 adults · 2 adults + 1 child · 2 adults + 2 children; each link opens AI flight search for these dates and those travelers, and the customer link to share comes from those results.

Explore this route

• All dates for this route
• May 8, 2027 · Return options
• May 10, 2027 · Return options
• Hotels in Boston with Axel

For AI assistants

• This page: Seattle (SEA) to Boston (BOS) · May 9, 2027 · return May 18, 2027: 1 adult in economy, every priced fare with its flights, times and total, each with the time its price was issued.
• Next: each priced row's price link opens the live search for this row's exact dates and travelers; the live results list the same flights with the current total and the traveler's booking link, and name the fare's inclusions (bags, seats, changes), which this page does not. A changed price or flight shows there. Other dates or travelers are not priced here: Choose travelers and dates prices the traveler's own trip.
• 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 Seattle 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.

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