ONT to SEA

Ontario to Seattle flight ticket price

Compare fares, departure times, stops and baggage details for this route, then open the full search when you are ready to check current availability and complete booking.

ONT
Ontario (ONT), United StatesOntario International
SEA
Seattle (SEA), United StatesSeattle/tacoma International
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Live flights for Sat, 06 Jun 2026

Review fares, stops, timings and baggage. Use Search or View all flights for the complete search result.

Showing flight options for the selected travel date.
Currency: USD
Sat, 06 JunONT to SEA$311 Sun, 07 JunONT to SEA Mon, 08 JunONT to SEA Tue, 09 JunONT to SEA Wed, 10 JunONT to SEA Thu, 11 JunONT to SEA Fri, 12 JunONT to SEA
Sort By:DepartureDurationArrivalPrice
United Airlines
United Airlines
UA-2446
05:00
2026-06-06
Ontario (ONT)United StatesOntario International
8H :24 M
1 Stop
DEN · 3h 04mDenver (DEN), United States
13:24
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
American Airlines
American Airlines
AA-1194
06:10
2026-06-06
Ontario (ONT)United StatesOntario International
8H :39 M
1 Stop
PHX · 3h 56mPhoenix (PHX), United States
14:49
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 4 Seat Left Economy
Cabin: Included
American Airlines
American Airlines
AA-2244
13:11
2026-06-06
Ontario (ONT)United StatesOntario International
7H :53 M
1 Stop
PHX · 3h 16mPhoenix (PHX), United States
21:04
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-1263
13:18
2026-06-06
Ontario (ONT)United StatesOntario International
8H :01 M
1 Stop
DEN · 2h 42mDenver (DEN), United States
21:19
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 2 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-1375
13:40
2026-06-06
Ontario (ONT)United StatesOntario International
5H :07 M
1 Stop
SFO · 1h 22mSan Francisco (SFO), United States
18:47
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 8 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-1375
13:40
2026-06-06
Ontario (ONT)United StatesOntario International
7H :13 M
1 Stop
SFO · 3h 23mSan Francisco (SFO), United States
20:53
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-5624
18:39
2026-06-06
Ontario (ONT)United StatesOntario International
4H :53 M
1 Stop
SFO · 1h 01mSan Francisco (SFO), United States
23:32
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-5624
18:39
2026-06-06
Ontario (ONT)United StatesOntario International
6H :34 M
1 Stop
SFO · 2h 50mSan Francisco (SFO), United States
01:13
2026-06-07
SEATTLE (SEA)United StatesSeattle/tacoma International
$311
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
Delta Air Lines
Delta Air Lines
DL-3816
06:45
2026-06-06
Ontario (ONT)United StatesOntario International
3H :02 M
Non Stop
09:47
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$331
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
Delta Air Lines
Delta Air Lines
DL-4070
11:52
2026-06-06
Ontario (ONT)United StatesOntario International
3H :01 M
Non Stop
14:53
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$331
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
Delta Air Lines
Delta Air Lines
DL-3840
13:35
2026-06-06
Ontario (ONT)United StatesOntario International
2H :58 M
Non Stop
16:33
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$331
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
Delta Air Lines
Delta Air Lines
DL-4031
17:45
2026-06-06
Ontario (ONT)United StatesOntario International
3H :00 M
Non Stop
20:45
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$331
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
Delta Air Lines
Delta Air Lines
DL-1006
13:29
2026-06-06
Ontario (ONT)United StatesOntario International
5H :17 M
1 Stop
SLC · 1h 13mSalt Lake City (SLC), United States
18:46
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$341
total fare
Non Refundable 9 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-2363
06:00
2026-06-06
Ontario (ONT)United StatesOntario International
6H :34 M
1 Stop
SFO · 2h 50mSan Francisco (SFO), United States
12:34
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$356
total fare
Non Refundable 6 Seat Left Economy
Cabin: Included
United Airlines
United Airlines
UA-1263
13:18
2026-06-06
Ontario (ONT)United StatesOntario International
10H :14 M
1 Stop
DEN · 1h 16mDenver (DEN), United States
23:32
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$362
total fare
Non Refundable 1 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-607
06:00
2026-06-06
Ontario (ONT)United StatesOntario International
2H :52 M
Non Stop
08:52
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$373
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-654
12:04
2026-06-06
Ontario (ONT)United StatesOntario International
2H :49 M
Non Stop
14:53
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$373
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-625
16:03
2026-06-06
Ontario (ONT)United StatesOntario International
2H :49 M
Non Stop
18:52
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$373
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-2440
15:35
2026-06-06
Ontario (ONT)United StatesOntario International
6H :50 M
1 Stop
STS · 3h 22mSanta Rosa (STS), United States
22:25
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$405
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-2199
17:57
2026-06-06
Ontario (ONT)United StatesOntario International
4H :37 M
1 Stop
PDX · 1h 14mPortland (PDX), United States
22:34
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$405
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-1333
11:15
2026-06-06
Ontario (ONT)United StatesOntario International
4H :21 M
1 Stop
PDX · 0h 51mPortland (PDX), United States
15:36
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$426
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
Alaska Airlines
Alaska Airlines
AS-2304
07:00
2026-06-06
Ontario (ONT)United StatesOntario International
4H :59 M
1 Stop
PDX · 1h 21mPortland (PDX), United States
11:59
2026-06-06
SEATTLE (SEA)United StatesSeattle/tacoma International
$485
total fare
Non Refundable 3 Seat Left Economy
Cabin: Included

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American Airlines
American Airlines
AA-991
23:59
2026-06-06
Ontario (ONT)United StatesOntario International
9H :34 M
1 Stop
DFW · 2h 10mDallas (DFW), United States
09:33
2026-06-07
SEATTLE (SEA)United StatesSeattle/tacoma International
$566
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
American Airlines
American Airlines
AA-1412
05:45
2026-06-06
Ontario (ONT)United StatesOntario International
27H :48 M
1 Stop
DFW · 20h 17mDallas (DFW), United States
09:33
2026-06-07
SEATTLE (SEA)United StatesSeattle/tacoma International
$572
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
American Airlines
American Airlines
AA-1412
05:45
2026-06-06
Ontario (ONT)United StatesOntario International
29H :04 M
1 Stop
DFW · 21h 27mDallas (DFW), United States
10:49
2026-06-07
SEATTLE (SEA)United StatesSeattle/tacoma International
$572
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
American Airlines
American Airlines
AA-2893
07:00
2026-06-06
Ontario (ONT)United StatesOntario International
26H :33 M
1 Stop
DFW · 19h 01mDallas (DFW), United States
09:33
2026-06-07
SEATTLE (SEA)United StatesSeattle/tacoma International
$572
total fare
Non Refundable 7 Seat Left Economy
Cabin: Included
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Fare highlights

Selected flight highlights for 06 Jun 2026.

Open full search
Lowest fare $311 United Airlines 05:00
Earliest departure $311 United Airlines 05:00
Shortest duration $373 Alaska Airlines 12:04
Night 00:00-05:59 $311 United Airlines at 05:00
Morning 06:00-11:59 $311 American Airlines at 06:10
Afternoon 12:00-17:59 $311 American Airlines at 13:11
Evening 18:00-23:59 $311 United Airlines at 18:39

Ontario to Seattle route details

Ontario (ONT)

Ontario International

United States

GMT -8

Latitude: 34.055999755859375

Longitude: -117.60099792480469

Seattle (SEA)

Seattle/tacoma International

United States

GMT -8

Latitude: 47.449001

Longitude: -122.308998

Distance: Ontario (ONT), United States to Seattle (SEA), United States - 1,540.37 km
Flights shown for 06 Jun 2026. View all flights opens the complete search result.

Ontario to Seattle - what to expect when booking

The ONT to SEA cards above show selected flight options. Airline prices and seat availability can move quickly, so the final fare is rechecked in the booking flow.

Approx route distance: 1,540.37 km.

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More flights from Ontario (ONT)14 routes
Ontario → Chicago
ONT → MDW
Ontario → Denver
ONT → DEN
Ontario → Dallas
ONT → DFW
Ontario → Guadalajara
ONT → GDL
Ontario → Houston
ONT → IAH
Ontario → Las Vegas
ONT → LAS
Ontario → Oakland
ONT → OAK
Ontario → Phoenix
ONT → PHX
Ontario → Portland
ONT → PDX
Ontario → Sacramento
ONT → SMF
Ontario → Salt Lake City
ONT → SLC
Ontario → San Francisco
ONT → SFO
Ontario → San Jose
ONT → SJC
Ontario → San Juan
ONT → SJU
More flights from Seattle (SEA)23 routes
Seattle → Albuquerque
SEA → ABQ
Seattle → Amsterdam
SEA → AMS
Seattle → Anchorage
SEA → ANC
Seattle → Atlanta
SEA → ATL
Seattle → Austin
SEA → AUS
Seattle → Beijing
SEA → PEK
Seattle → Bellingham
SEA → BLI
Seattle → Billings
SEA → BIL
Seattle → Boise
SEA → BOI
Seattle → Boston
SEA → BOS
Seattle → Bozeman
SEA → BZN
Seattle → Burbank
SEA → BUR
Seattle → Calgary
SEA → YYC
Seattle → Charlotte
SEA → CLT
Seattle → Chicago
SEA → MDW
Seattle → Colorado Springs
SEA → COS
Seattle → Dallas
SEA → DAL
Seattle → Denver
SEA → DEN
Seattle → Detroit Mi
SEA → DTW
Seattle → Dubai
SEA → DXB
Seattle → Edmonton
SEA → YEG
Seattle → Eugene
SEA → EUG
Seattle → Fairbanks
SEA → FAI
Frequently asked questions - Ontario to Seattle flights
Generally yes. When your travel date is fixed, comparing live fares early gives you better visibility of timings, baggage and fare rules before prices change.
The approximate route distance between Ontario (ONT) and Seattle (SEA) is 1,540.37 km. Actual flying distance can vary by airline routing.
Availability changes by airline schedule and date. Use the Stops filter to quickly check non-stop, one-stop and connecting options on this landing page.
Airline inventory can change within minutes. Book Now sends the selected result to the review flow where the fare is checked again before final booking.
Yes. The date strip and search box open the full search for the selected date, while this page keeps the route details easy to compare.