Route guide

Ontario to Seattle (ONT-SEA): Nonstop Upgrade & Award Space

Alaska Airlines, Inc., Delta Air Lines, and Frontier Airlines fly nonstop between Ontario (ONT) and Seattle (SEA), roughly 59 times a week. Because so many carriers compete on this route, premium seats turn over daily, and upgrade or award space can open and close within hours. 2LNR tracks confirmed availability on every ONT to SEA departure, so you know which flights have space before you book.

Data current as of July 21, 2026, refreshed on an ongoing basis as new schedules and seats are confirmed.

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59
Nonstop flights a week
957 mi
Nonstop distance
Free
To get started

Confirmed upgrade & award space on every ONT to SEA departure

2LNR tracks confirmed upgrade and award availability on American, Delta, and Alaska and across 30 airlines, segment by segment, date by date. Open the calendar for Ontario to Seattle to see which departures have real space, or watch the route and get alerted when space opens.

See real availability

Confirmed upgrade and award seats on each ONT to SEA departure, checked against live inventory so you know what is open before you book.

Set an alert

Premium inventory turns over fast. Watch this route and 2LNR notifies you when space appears on a date you are tracking.

Plan on the map

See ONT to SEA on the interactive route map, with schedules, connections, and route statistics.

Airlines flying Ontario to Seattle nonstop

Carriers operating ONT to SEA nonstop in the current schedule. 2LNR tracks confirmed upgrade and award space on each of them.

  • Alaska Airlines, Inc.
  • Delta Air Lines
  • Frontier Airlines
See ONT to SEA on the interactive map →

Frequently asked questions about ONT to SEA

How far is Seattle from Ontario?
ONT to SEA covers about 957 miles nonstop. Flight times vary by aircraft and season; each scheduled departure on this page lists its own times.
Which airlines fly nonstop from ONT to SEA?
Alaska Airlines, Inc., Delta Air Lines, and Frontier Airlines fly the route nonstop. 2LNR tracks confirmed upgrade and award space on all three of them.
How many flights a week are there from ONT to SEA?
About 59 nonstop flights a week run between Ontario and Seattle in the current schedule, operated by Alaska Airlines, Inc., Delta Air Lines, and Frontier Airlines. Frequency shifts by season; the calendar on this page reflects what's currently scheduled.
How do I check upgrade or award availability on ONT to SEA?
Open the ONT to SEA calendar on this page to see confirmed upgrade and award space by date. You can also set an alert on the Ontario to Seattle route, and 2LNR will notify you when space opens. It's free to start.

Never miss ONT to SEA upgrade or award space

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