--- title: "Ontario (ONT) to Seattle (SEA) flights: who flies it" description: "Alaska Airlines, Delta Air Lines and Frontier Airlines fly nonstop from ONT to SEA, about 60 flights a week. Upgrade and award space by date on 2LNR, next 14 days free." canonical: "https://2lnr.com/routes/ont-sea" url: "https://2lnr.com/routes/ont-sea.md" date_modified: "2026-10-25T05:37:10Z" --- # Ontario to Seattle (ONT-SEA): nonstop upgrade & award space Alaska Airlines, Delta Air Lines, and Frontier Airlines fly nonstop between Ontario (ONT) and Seattle (SEA), roughly 60 times a week. The timetable below shows the nonstop scheduled at 2h 43m to 3h 4m for the 957 miles. 2LNR checks confirmed upgrade and award space on Alaska Airlines and Delta Air Lines flights on this route, so you can see which departures have space before you book. Schedule last confirmed October 25, 2026. Departure times come from 2LNR's schedule data; confirm with the airline before you book. Updated October 29, 2026. See ONT to SEA on the interactive map [Get started free](https://2lnr.com/login) 60 Flights a week, 4-week average 2h 43m to 3h 4m Scheduled flight time 957 mi Nonstop distance Free To get started ## Ontario to Seattle flight schedule Scheduled nonstop departures for ONT to SEA starting October 28, 2026, last checked against our schedule feed on October 25, 2026. Airlines retime and cancel flights, so confirm with the airline before you book. Scheduled nonstop departures from Ontario (ONT) to Seattle (SEA) | Date | Flight | Airline | Departs ONT | Arrives SEA | Duration | Aircraft | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | Wed, Oct 28 | AS 607 | Alaska Airlines, Inc. | 06:02 | 08:49 | 2h 47m | [Boeing 737-900](https://2lnr.com/seatmaps/as/737-900.md) | | Wed, Oct 28 | DL 3816 | Delta Air Lines | 06:20 | 09:24 | 3h 4m | [Embraer E175](https://2lnr.com/seatmaps/dl/e175.md) | | Wed, Oct 28 | AS 475 | Alaska Airlines, Inc. | 11:13 | 13:56 | 2h 43m | [Boeing 737-800](https://2lnr.com/seatmaps/as/737-800.md) | | Wed, Oct 28 | DL 4070 | Delta Air Lines | 11:56 | 14:55 | 2h 59m | Embraer E175 | | Wed, Oct 28 | AS 575 | Alaska Airlines, Inc. | 14:13 | 16:56 | 2h 43m | Boeing 737-800 | | Wed, Oct 28 | F9 2275 | Frontier Airlines | 17:05 | 20:01 | 2h 56m | [Airbus A321](https://2lnr.com/seatmaps/f9/a321.md) | | Wed, Oct 28 | DL 4031 | Delta Air Lines | 18:00 | 20:59 | 2h 59m | Embraer E175 | | Wed, Oct 28 | AS 592 | Alaska Airlines, Inc. | 18:56 | 21:41 | 2h 45m | Boeing 737-900 | | Thu, Oct 29 | AS 607 | Alaska Airlines, Inc. | 06:02 | 08:49 | 2h 47m | Boeing 737-900 | | Thu, Oct 29 | DL 3816 | Delta Air Lines | 06:20 | 09:24 | 3h 4m | Embraer E175 | | Thu, Oct 29 | AS 475 | Alaska Airlines, Inc. | 11:13 | 13:56 | 2h 43m | [Boeing 737 MAX 9](https://2lnr.com/seatmaps/as/737-max-9.md) | | Thu, Oct 29 | DL 4070 | Delta Air Lines | 11:56 | 14:55 | 2h 59m | Embraer E175 | | Thu, Oct 29 | AS 575 | Alaska Airlines, Inc. | 14:13 | 16:56 | 2h 43m | Boeing 737 MAX 9 | | Thu, Oct 29 | F9 2275 | Frontier Airlines | 17:06 | 20:08 | 3h 2m | [Airbus A320neo](https://2lnr.com/seatmaps/f9/a320neo.md) | | Thu, Oct 29 | DL 4031 | Delta Air Lines | 18:00 | 20:59 | 2h 59m | Embraer E175 | | Thu, Oct 29 | AS 592 | Alaska Airlines, Inc. | 18:56 | 21:39 | 2h 43m | Boeing 737-900 | | Fri, Oct 30 | AS 607 | Alaska Airlines, Inc. | 06:02 | 08:49 | 2h 47m | Boeing 737-900 | | Fri, Oct 30 | DL 3816 | Delta Air Lines | 06:20 | 09:24 | 3h 4m | Embraer E175 | | Fri, Oct 30 | AS 475 | Alaska Airlines, Inc. | 11:13 | 13:56 | 2h 43m | Boeing 737 MAX 9 | | Fri, Oct 30 | DL 4070 | Delta Air Lines | 11:56 | 14:55 | 2h 59m | Embraer E175 | | Fri, Oct 30 | AS 575 | Alaska Airlines, Inc. | 14:13 | 16:56 | 2h 43m | Boeing 737-900 | | Fri, Oct 30 | F9 2275 | Frontier Airlines | 17:06 | 20:08 | 3h 2m | Airbus A320neo | | Fri, Oct 30 | DL 4031 | Delta Air Lines | 18:00 | 20:59 | 2h 59m | Embraer E175 | | Fri, Oct 30 | AS 592 | Alaska Airlines, Inc. | 18:56 | 21:39 | 2h 43m | Boeing 737 MAX 9 | | Sat, Oct 31 | AS 607 | Alaska Airlines, Inc. | 06:02 | 08:49 | 2h 47m | Boeing 737-900 | | Sat, Oct 31 | DL 3816 | Delta Air Lines | 06:20 | 09:24 | 3h 4m | Embraer E175 | | Sat, Oct 31 | AS 475 | Alaska Airlines, Inc. | 11:13 | 13:56 | 2h 43m | Boeing 737-900 | | Sat, Oct 31 | DL 4070 | Delta Air Lines | 11:55 | 14:58 | 3h 3m | Embraer E175 | | Sat, Oct 31 | AS 575 | Alaska Airlines, Inc. | 14:13 | 16:56 | 2h 43m | Boeing 737 MAX 9 | | Sat, Oct 31 | F9 2275 | Frontier Airlines | 17:05 | 20:01 | 2h 56m | Airbus A321 | | Sat, Oct 31 | DL 4031 | Delta Air Lines | 18:00 | 20:59 | 2h 59m | Embraer E175 | | Sat, Oct 31 | AS 592 | Alaska Airlines, Inc. | 18:56 | 21:41 | 2h 45m | Boeing 737-900 | | Sun, Nov 1 | AS 607 | Alaska Airlines, Inc. | 06:00 | 08:51 | 2h 51m | Boeing 737-900 | | Sun, Nov 1 | DL 3816 | Delta Air Lines | 06:20 | 09:24 | 3h 4m | Embraer E175 | | Sun, Nov 1 | DL 4070 | Delta Air Lines | 11:56 | 14:55 | 2h 59m | Embraer E175 | | Sun, Nov 1 | AS 575 | Alaska Airlines, Inc. | 12:02 | 14:49 | 2h 47m | Boeing 737-900 | | Sun, Nov 1 | AS 571 | Alaska Airlines, Inc. | 16:09 | 18:56 | 2h 47m | Boeing 737-900 | | Sun, Nov 1 | F9 2275 | Frontier Airlines | 17:27 | 20:29 | 3h 2m | Airbus A320neo | | Sun, Nov 1 | DL 4031 | Delta Air Lines | 18:00 | 20:59 | 2h 59m | Embraer E175 | | Sun, Nov 1 | AS 594 | Alaska Airlines, Inc. | 19:13 | 22:00 | 2h 47m | Boeing 737 MAX 9 | Showing the first 40 of 56 scheduled ONT to SEA departures across 7 days with service, starting October 28, 2026. Every remaining date is on the interactive map. Departure and arrival times are local at their own airport, so an arrival can fall on a different local date than the departure; the duration column is the true elapsed flying time. A dash means the airline hasn't filed that value in the schedule data we hold. Aircraft are the equipment the airline filed, named where the code pins down one type and shown as the family or the bare code where it doesn't. Swaps can happen up to departure. See every ONT to SEA date on the interactive map ## Aircraft on the Ontario to Seattle nonstop In the schedule table on this page, Alaska Airlines flies the [Boeing 737-900](https://2lnr.com/seatmaps/as/737-900.md), the [Boeing 737 MAX 9](https://2lnr.com/seatmaps/as/737-max-9.md), and the [Boeing 737-800](https://2lnr.com/seatmaps/as/737-800.md). Delta Air Lines flies the [Embraer E175](https://2lnr.com/seatmaps/dl/e175.md). Frontier Airlines flies the [Airbus A320neo](https://2lnr.com/seatmaps/f9/a320neo.md) and the [Airbus A321](https://2lnr.com/seatmaps/f9/a321.md). Each linked aircraft page shows where that airline schedules it. Airlines can swap aircraft up to departure. ## Confirmed upgrade & award space on ONT to SEA departures 2LNR tracks confirmed upgrade and award space on Alaska Airlines and Delta Air Lines, segment by segment and date by date. Open the calendar for Ontario to Seattle to see which departures have space, the next 14 days free on every product and the full horizon on Pro. In the 7 days to October 26, 2026, 2LNR checked award space on Ontario to Seattle departures from October 26 to November 8. Alaska Airlines had space open on 13 of 14 dates checked and Delta Air Lines on 14 of 14. ### See real availability Confirmed upgrade or award seats by date on the ONT to SEA departures 2LNR tracks, checked against live inventory so you know what's open before you book. ### Set an alert Premium inventory turns over fast. Watch this route on Pro and 2LNR notifies you when space appears on a date you're 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. Where 2LNR tracks the carrier, its departures show confirmed upgrade or award space by date. - [Alaska Airlines (AS) route map](https://2lnr.com/routes/airlines/as.md)\ [The aircraft AS flies](https://2lnr.com/seatmaps/as.md) - [Delta Air Lines (DL) route map](https://2lnr.com/routes/airlines/dl.md)\ [The aircraft DL flies](https://2lnr.com/seatmaps/dl.md) - [Frontier Airlines (F9) route map](https://2lnr.com/routes/airlines/f9.md)\ [The aircraft F9 flies](https://2lnr.com/seatmaps/f9.md) See ONT to SEA on the interactive map → ## Frequently asked questions about ONT to SEA **How long is the flight from Ontario (ONT) to Seattle (SEA)?** Scheduled flight times from Ontario (ONT) to Seattle (SEA) run from 2h 43m to 3h 4m across the departures in the schedule table on this page. The nonstop covers about 957 miles, and airlines adjust scheduled times by season, so confirm with the airline before you book. **Which airlines fly nonstop from ONT to SEA?** Alaska Airlines, Delta Air Lines, and Frontier Airlines fly ONT to SEA nonstop. 2LNR tracks confirmed upgrade and award space on Alaska Airlines and Delta Air Lines. **How many flights a week are there from ONT to SEA?** About 60 nonstop flights a week run between Ontario (ONT) and Seattle (SEA) in the current schedule, operated by Alaska Airlines, Delta Air Lines, and Frontier Airlines. Frequency shifts by season, and the schedule table on this page shows what is scheduled next. **What time do flights from ONT to SEA depart?** Scheduled ONT to SEA nonstops in the next 7 days with service leave between 06:00 and 19:13, local time at Ontario. The schedule table on this page lists every departure by date, with its arrival time and aircraft. **Which flights operate ONT to SEA nonstop?** The schedule table on this page lists 10 flight numbers for ONT to SEA nonstops, including AS 475, AS 575, AS 592, and AS 607 on Alaska Airlines; DL 3816, DL 4031, and DL 4070 on Delta Air Lines; and F9 2275 on Frontier Airlines. The table lists each departure by date with its times and aircraft. **How do I check upgrade or award availability on ONT to SEA?** Open the ONT to SEA route on the interactive map or the matrix to see confirmed upgrade and award space by date on Alaska Airlines and Delta Air Lines, the next 14 days free and the full horizon on Pro. On Pro you can also set an alert on the route and 2LNR notifies you when space opens. Flying the other way? See [SEA to ONT upgrade and award space](https://2lnr.com/routes/sea-ont.md). Award seats rather than schedules? See [Alaska Airlines award availability](https://2lnr.com/awards/as.md) or [Delta Air Lines award availability](https://2lnr.com/awards/dl.md). Looking beyond this route? See [every route from Ontario (ONT)](https://2lnr.com/routes/ont.md), or [every route from Seattle (SEA)](https://2lnr.com/routes/sea.md). Nonstops to Seattle (SEA) from other airports within 150 miles of Ontario (ONT): - [Santa Ana (SNA) to Seattle (SEA)](https://2lnr.com/routes/sna-sea.md), 30 miles from ONT - [Long Beach (LGB) to Seattle (SEA)](https://2lnr.com/routes/lgb-sea.md), 36 miles from ONT - [Burbank (BUR) to Seattle (SEA)](https://2lnr.com/routes/bur-sea.md), 45 miles from ONT - [Los Angeles (LAX) to Seattle (SEA)](https://2lnr.com/routes/lax-sea.md), 48 miles from ONT - [Palm Springs (PSP) to Seattle (SEA)](https://2lnr.com/routes/psp-sea.md), 64 miles from ONT Nonstops from Ontario (ONT) to other airports within 150 miles of Seattle (SEA): - [Ontario (ONT) to Portland (PDX)](https://2lnr.com/routes/ont-pdx.md), 129 miles from SEA Distances are great-circle between the airports, not driving distance. - [How Alaska upgrades clear](https://2lnr.com/about/as/upgrades.md) - [How to read award availability by date](https://2lnr.com/guides/award-availability.md) ## Never miss ONT to SEA upgrade or award space See what's open by date on this route, the next 14 days free on every product and the full horizon on Pro. [Get started free](https://2lnr.com/login)