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Showing 25
of 172
live flights
Frontier Airlines
F9-1176
19:50
05/11/2026
SEA
Seattle Tacoma International Airport
14h 15m
1 Stop
⏱ DEN · 8h 47m DEN Airport
10:05
05/12/2026
+1
ONT
Ontario International Airport
₹9,456
per person
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✕ Non-refundable
Frontier Airlines
F9-2408
11:37
05/11/2026
SEA
Seattle Tacoma International Airport
7h 55m
1 Stop
⏱ LAS · 4h 2m LAS Airport
19:32
05/11/2026
ONT
Ontario International Airport
₹9,456
per person
Select →
✕ Non-refundable
Frontier Airlines
F9-1176
19:50
05/11/2026
SEA
Seattle Tacoma International Airport
27h 59m
1 Stop
⏱ DEN · 22h 35m DEN Airport
23:49
05/12/2026
+1
ONT
Ontario International Airport
₹11,455
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-2650
12:55
05/11/2026
SEA
Seattle Tacoma International Airport
10h 10m
1 Stop
⏱ LAS · 6h 35m LAS Airport
23:05
05/11/2026
ONT
Ontario International Airport
₹14,345
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-431
06:15
05/11/2026
SEA
Seattle Tacoma International Airport
5h 5m
1 Stop
⏱ LAS · 1h 35m LAS Airport
11:20
05/11/2026
ONT
Ontario International Airport
₹14,345
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-1310
05:30
05/11/2026
SEA
Seattle Tacoma International Airport
7h 40m
1 Stop
⏱ DEN · 2h 45m DEN Airport
13:10
05/11/2026
ONT
Ontario International Airport
₹14,345
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-2650
12:55
05/11/2026
SEA
Seattle Tacoma International Airport
7h 45m
1 Stop
⏱ LAS · 4h 5m LAS Airport
20:40
05/11/2026
ONT
Ontario International Airport
₹14,345
per person
Select →
✕ Non-refundable 5 fare options
05:30
05/11/2026
SEA
Seattle Tacoma International Airport
6h 23m
1 Stop
⏱ SLC · 2h 17m SLC Airport
11:53
05/11/2026
LGB
Ontario International Airport
₹15,397
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-2862
05:00
05/11/2026
SEA
Seattle Tacoma International Airport
4h 50m
1 Stop
⏱ SMF · 1h 40m SMF Airport
09:50
05/11/2026
BUR
Ontario International Airport
₹15,573
per person
Select →
✓ Refundable 8 fare options
Southwest Airlines
WN-431
06:15
05/11/2026
SEA
Seattle Tacoma International Airport
5h 25m
1 Stop
⏱ LAS · 1h 45m LAS Airport
11:40
05/11/2026
BUR
Ontario International Airport
₹15,573
per person
Select →
✓ Refundable 8 fare options
08:38
05/11/2026
SEA
Seattle Tacoma International Airport
5h 18m
1 Stop
⏱ SFO · 1h 33m SFO Airport
13:56
05/11/2026
BUR
Ontario International Airport
₹16,138
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-431
06:15
05/11/2026
SEA
Seattle Tacoma International Airport
9h 35m
1 Stop
⏱ LAS · 6h 0m LAS Airport
15:50
05/11/2026
ONT
Ontario International Airport
₹16,230
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-3588
07:20
05/11/2026
SEA
Seattle Tacoma International Airport
10h 0m
1 Stop
⏱ OAK · 6h 25m OAK Airport
17:20
05/11/2026
ONT
Ontario International Airport
₹16,230
per person
Select →
✕ Non-refundable
07:08
05/11/2026
SEA
Seattle Tacoma International Airport
6h 48m
1 Stop
⏱ SFO · 3h 4m SFO Airport
13:56
05/11/2026
BUR
Ontario International Airport
₹16,231
per person
Select →
✓ Refundable 🔥 Last 5 seats 4 fare options
Southwest Airlines
WN-3936
06:30
05/11/2026
SEA
Seattle Tacoma International Airport
9h 55m
1 Stop
⏱ PHX · 5h 55m PHX Airport
16:25
05/11/2026
ONT
Ontario International Airport
₹16,231
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-4204
11:40
05/11/2026
SEA
Seattle Tacoma International Airport
5h 10m
1 Stop
⏱ SMF · 1h 45m SMF Airport
16:50
05/11/2026
ONT
Ontario International Airport
₹16,231
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-4204
11:40
05/11/2026
SEA
Seattle Tacoma International Airport
8h 5m
1 Stop
⏱ SMF · 4h 35m SMF Airport
19:45
05/11/2026
ONT
Ontario International Airport
₹16,231
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-3588
07:20
05/11/2026
SEA
Seattle Tacoma International Airport
4h 50m
1 Stop
⏱ OAK · 1h 15m OAK Airport
12:10
05/11/2026
ONT
Ontario International Airport
₹17,051
per person
Select →
✕ Non-refundable 9 fare options
Southwest Airlines
WN-4200
18:15
05/11/2026
SEA
Seattle Tacoma International Airport
4h 50m
1 Stop
⏱ PHX · 0h 45m PHX Airport
23:05
05/11/2026
ONT
Ontario International Airport
₹17,051
per person
Select →
✕ Non-refundable 9 fare options
Southwest Airlines
WN-2862
05:00
05/11/2026
SEA
Seattle Tacoma International Airport
5h 25m
1 Stop
⏱ SMF · 2h 10m SMF Airport
10:25
05/11/2026
ONT
Ontario International Airport
₹17,051
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-2615
17:35
05/11/2026
SEA
Seattle Tacoma International Airport
5h 30m
1 Stop
⏱ LAS · 1h 55m LAS Airport
23:05
05/11/2026
ONT
Ontario International Airport
₹17,051
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-2862
05:00
05/11/2026
SEA
Seattle Tacoma International Airport
7h 55m
1 Stop
⏱ SMF · 4h 40m SMF Airport
12:55
05/11/2026
ONT
Ontario International Airport
₹17,577
per person
Select →
✕ Non-refundable 5 fare options
Southwest Airlines
WN-4204
11:40
05/11/2026
SEA
Seattle Tacoma International Airport
15:35
05/11/2026
BUR
Ontario International Airport
₹17,979
per person
Select →
✕ Non-refundable
Southwest Airlines
WN-4204
11:40
05/11/2026
SEA
Seattle Tacoma International Airport
3h 55m
1 Stop
⏱ SMF · 0h 35m SMF Airport
15:35
05/11/2026
BUR
Ontario International Airport
₹18,131
per person
Select →
✓ Refundable 8 fare options
Southwest Airlines
WN-431
06:15
05/11/2026
SEA
Seattle Tacoma International Airport
11h 55m
2 Stops
⏱ SNA · 1h 30m SNA Airport ⏱ SJC · 3h 30m SJC Airport
18:10
05/11/2026
ONT
Ontario International Airport
₹18,224
per person
Select →
✕ Non-refundable 4 fare options
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Seattle (SEA)
📍 Seattle Tacoma International Airport
🌍 United States
🕐 GMT -8
📐 Latitude: 47.449001
📐 Longitude: -122.308998
Ontario (ONT)
📍 Ontario International Airport
🌍 United States
🕐 GMT -8
📐 Latitude: 34.055999755859375
📐 Longitude: -117.60099792480469
✈ Distance: Seattle,USA to Ontario,USA — 1540.37 km
📅 Results on this page are loaded for 11 May 2026 . Click View all flights for the complete live search.
Seattle to Ontario — what to expect when booking
The SEA–ONT route is served by multiple carriers throughout the year.
Fares on this route can move quickly — a price available now may not be there 30 minutes later.
If your dates are flexible, try shifting your departure by a day or two using the date strip above.
Mid-week departures often show lower base fares compared to weekend starts on many routes.
The distance between Seattle,USA and Ontario,USA is approximately
1540.37 km .
Before you book
Compare nearby dates The date strip above lets you scan nearby fares without restarting the search.
Open full search for more control Route page shows a limited live set. Full search opens the complete inventory with fresh results.
Check fare details Each result shows baggage, refundability and fare details before you proceed.
More flights from Seattle (SEA)
87 routes
More flights from Ontario (ONT)
15 routes
❓ Frequently asked questions — Seattle to Ontario flights
▼ Is it worth booking Seattle to Ontario flights in advance?
Generally yes — fares on most routes are most competitive around 4–6 weeks before departure. Booking earlier usually means better availability and a lower base fare when your dates are fixed.
▼ How far is Seattle from Ontario by air?
The straight-line distance between Seattle,USA (SEA) and Ontario,USA (ONT) is approximately 1540.37 km. Actual flying distance may vary slightly depending on routing.
▼ Are there non-stop flights from SEA to ONT?
Non-stop availability on this route varies by airline schedule and season. Use the filters below to quickly check whether direct options are available on your selected date.
▼ What is the cheapest day to fly from Seattle to Ontario?
Mid-week departures often show lower prices than weekend travel on many routes. Use the date strip above to compare nearby days quickly.