Seattle (SEA) to Ontario (ONT) · Dec 18, 2026 · return Dec 21, 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 Ontario (ONT) flight deals

2026-12-18 → 2026-12-21 · Axel-exclusive $198.00

• Frontier Airlines F92276: SEA 2026-12-18 10:18:00 → ONT 2026-12-18 13:06:00; nonstop; 168 minutes. Local airport times.
• Frontier Airlines F92275: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 09:03:00; nonstop; 183 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $334.80

• Alaska Airlines AS571: SEA 2026-12-18 13:33:00 → ONT 2026-12-18 16:05:00; nonstop; 152 minutes. Local airport times.
• Alaska Airlines AS677: ONT 2026-12-21 11:57:00 → SEA 2026-12-21 14:49:00; nonstop; 172 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $346.80

• Delta Air Lines DL4070: SEA 2026-12-18 08:25:00 → ONT 2026-12-18 11:17:00; nonstop; 172 minutes. Local airport times.
• Delta Air Lines DL4031: ONT 2026-12-21 17:38:00 → SEA 2026-12-21 20:43:00; nonstop; 185 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $379.80

• American Airlines AA2073 / AA1841: SEA 2026-12-18 15:00:00 → ONT 2026-12-18 21:52:00; 1 stop(s) via PHX; 412 minutes. Local airport times.
  • AA2073: SEA 2026-12-18 15:00:00 → PHX 2026-12-18 18:52:00; layover at PHX: 163 minutes.
  • AA1841: PHX 2026-12-18 21:35:00 → ONT 2026-12-18 21:52:00.
• Delta Air Lines DL4031: ONT 2026-12-21 17:38:00 → SEA 2026-12-21 20:43:00; nonstop; 185 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $382.80

• Southwest Airlines WN3105 / WN1383: SEA 2026-12-18 08:05:00 → ONT 2026-12-18 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
  • WN3105: SEA 2026-12-18 08:05:00 → SJC 2026-12-18 10:20:00; layover at SJC: 60 minutes.
  • WN1383: SJC 2026-12-18 11:20:00 → ONT 2026-12-18 12:40:00.
• Southwest Airlines WN1053 / WN4083: ONT 2026-12-21 17:00:00 → SEA 2026-12-21 22:20:00; 1 stop(s) via LAS; 320 minutes. Local airport times.
  • WN1053: ONT 2026-12-21 17:00:00 → LAS 2026-12-21 18:05:00; layover at LAS: 85 minutes.
  • WN4083: LAS 2026-12-21 19:30:00 → SEA 2026-12-21 22:20:00.

2026-12-18 → 2026-12-21 · Axel-exclusive $430.80

• United Airlines UA2478 / UA552: SEA 2026-12-18 15:24:00 → ONT 2026-12-18 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
  • UA2478: SEA 2026-12-18 15:24:00 → SFO 2026-12-18 17:45:00; layover at SFO: 225 minutes.
  • UA552: SFO 2026-12-18 21:30:00 → ONT 2026-12-18 22:53:00.
• United Airlines UA2363 / UA2192: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
  • UA2363: ONT 2026-12-21 06:00:00 → SFO 2026-12-21 07:30:00; layover at SFO: 155 minutes.
  • UA2192: SFO 2026-12-21 10:05:00 → SEA 2026-12-21 12:18:00.

2026-12-18 → 2026-12-21 · Axel-exclusive $334.80

• Alaska Airlines AS489: SEA 2026-12-18 21:23:00 → ONT 2026-12-18 23:59:00; nonstop; 156 minutes. Local airport times.
• Alaska Airlines AS677: ONT 2026-12-21 11:57:00 → SEA 2026-12-21 14:49:00; nonstop; 172 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $228.00

• Frontier Airlines F92408 / F91923: SEA 2026-12-18 11:53:00 → ONT 2026-12-18 18:31:00; 1 stop(s) via LAS; 398 minutes. Local airport times.
  • F92408: SEA 2026-12-18 11:53:00 → LAS 2026-12-18 14:32:00; layover at LAS: 173 minutes.
  • F91923: LAS 2026-12-18 17:25:00 → ONT 2026-12-18 18:31:00.
• Frontier Airlines F92275: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 09:03:00; nonstop; 183 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $362.80

• Alaska Airlines AS3087 / AS3380: SEA 2026-12-18 09:50:00 → ONT 2026-12-18 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
  • AS3087: SEA 2026-12-18 09:50:00 → BOI 2026-12-18 12:21:00; layover at BOI: 199 minutes.
  • AS3380: BOI 2026-12-18 15:40:00 → ONT 2026-12-18 16:56:00.
• Alaska Airlines AS677: ONT 2026-12-21 11:57:00 → SEA 2026-12-21 14:49:00; nonstop; 172 minutes. Local airport times.

2026-12-18 → 2026-12-21 · Axel-exclusive $374.80

• Delta Air Lines DL1016 / DL3879: SEA 2026-12-18 09:18:00 → ONT 2026-12-18 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
  • DL1016: SEA 2026-12-18 09:18:00 → SLC 2026-12-18 12:31:00; layover at SLC: 178 minutes.
  • DL3879: SLC 2026-12-18 15:29:00 → ONT 2026-12-18 16:22:00.
• Delta Air Lines DL4031: ONT 2026-12-21 17:38:00 → SEA 2026-12-21 20:43:00; nonstop; 185 minutes. Local airport times.

Explore this route

• All dates for this route
• Dec 17, 2026 · Return options
• Dec 19, 2026 · Return options

For AI assistants

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