$242 Cheap United flights from Ontario to Seattle (ONT to SEA)

Find The Best Day To Fly from Ontario to Seattle

Amazing United ONT to SEA Flight Deals

The cheapest flights to Seattle - Tacoma Intl. found within the past 7 days were $378 round trip and $242 one way. Prices and availability subject to change. Additional terms may apply.

Sat, Aug 31 - Tue, Sep 3
ONT
Ontario
SEA
Seattle
$378 Roundtrip, found 2 hours ago
$378
Roundtrip
found 2 hours ago
Select United flight, departing Sat, Aug 31 from Ontario to Seattle, returning Tue, Sep 3, priced at $378 found 2 hours ago

SEA From ONT Economy Coach Packages on Similar Airlines

Mediterranean Inn

Mediterranean Inn

3 out of 5
Save 100% on your flight
per person
Jun 29 - Jul 5
Roundtrip flight included
Ontario (ONT) to Seattle (SEA)
The Belltown Inn

The Belltown Inn

2.5 out of 5
Save 100% on your flight
per person
Jun 29 - Jul 5
Roundtrip flight included
Ontario (ONT) to Seattle (SEA)
Hotel Max

Hotel Max

3.5 out of 5
Save 100% on your flight
per person
Jun 29 - Jul 5
Roundtrip flight included
Ontario (ONT) to Seattle (SEA)
Don't see what you're looking for?
See all available trips from Los Angeles - Ontario Intl. to Seattle - Tacoma Intl.
View all trips
Prices and availability subject to change. Additional terms may apply.

Frequently asked questions

Can I catch a flight from Ontario Airport to Seattle - Tacoma Intl. Airport (SEA) right now?
For any current Seattle - Tacoma Intl. Airport (SEA) travel advice and quarantine requirements, visit our Covid-19 Travel Advisor. Look before you arrange your flight, so you don’t get caught up en route.
What terminal is United Airlines at ONT?
The information printed on boarding passes often differs from airline to airline. If you’re traveling from Ontario Airport to Sea-Tac Airport with United Airlines and you can’t locate your terminal details, contact the airline.
Are there United Airlines non-stop flights from ONT to SEA?
United Airlines doesn’t have direct flights between ONT and SEA, so expect to make a stopover. If you have time to spare between flights, enjoy a coffee while you wait for your connection.
How long is a United Airlines flight from ONT to SEA?
No horrible jet lag, no aching legs — there’s plenty to love about short-haul flights. If you’re traveling with United Airlines from ONT to Seattle - Tacoma Intl. Airport (SEA), the plane ride will fly by in roughly 3 hours and 50 minutes.
How many direct and indirect flights does United Airlines fly from ONT to SEA?
Take your pick of about 4 flights per day with United Airlines from Ontario Airport to Sea-Tac Airport.
If I am not able to travel due to COVID-19, can I change my booking to a later date?
For more info about changing your flight to Seattle - Tacoma Intl. Airport (SEA), please visit our Customer Service Portal.
What is the best day to buy a plane ticket?
This just in! Airfares offered on Thursdays tend to be the cheapest, according to flight demand on Travelocity in 2021. Tuesday and Wednesday prices are also good, but you may want to prepare your budget if booking during the weekend, as data shows that is when prices are generally at their highest.
What are the cheapest days to fly?
Frequent travelers may already know this, but earlier in the week can be the cheapest time to fly. In 2021, flights departing on a Monday were generally the cheapest of the week, whereas you may pay a premium for weekend flights when demand is usually high. On average, tickets were most expensive for Saturday departures, so if you need to fly out on a weekend, you might look for deals ahead of time.
How far in advance can you book a flight?
Trying to figure out how early you should book your flight? It’s possible to start comparing international airfares on Travelocity up to 12 months in advance. However, it does depend on the carrier as not all airlines release their prices that far out. According to our 2021 flight demand trends, last minute planners can still bag a bargain with some of the cheapest fares appearing 0-2 weeks prior to their travel dates.*According to flight demand on Travelocity.com from January to December 2021. Savings are subject to change based on departure location, date and destination.

Discover our best United flight from Ontario ONT to Seattle SEA 

To find the best deals on flights to Ontario from Seattle with United, just enter your travel dates, filter by United, and hit search. You’ll find flights to choose from and can sort by price, flight duration, and arrival or departure time.  

 

Return flights from Ontario ONT to Seattle SEA with United 

If you’re planning a round trip, booking return flights with United is usually the most cost-effective option. With airfares ranging from $378 to $378, it’s easy to find a flight that suits your budget. Prices and availability subject to change. Additional terms may apply. 

 

Book one-way United flights from Ontario ONT to Seattle SEA 

A one-way ticket gives you much greater flexibility—allowing you to choose your return date, destination, and time whenever you’re ready. By booking in advance you can find great deals on one-way tickets too. Right now, a one-way United flight from Ontario to Seattle costs from $242. Prices and availability subject to change. Additional terms may apply. 

 

The easy way to find cheap flights to Seattle SEA from  Ontario ONT with United 

To find a cheap United flight from Ontario ONT to Seattle SEA, sort your search results by price or filter by budget. Thanks to Travelocity’s Price Match Promise, if you find a better airfare deal anywhere else within 24 hours, we’ll credit or refund the difference. 

 

How to find our best airfare deals on United flights from Ontario ONT to Seattle SEA 

If you’re looking for cheap flights, it helps to be flexible when it comes to your travel dates. You’ll usually find lower cost tickets when you travel during quieter months such as August, or if you book a flight with a stopover. 

 

Find nonstop flights from Ontario ONT to Seattle SEA with United 

If you’re keen to be on Seattle soil fast, don’t waste time with a stopover—filter your search results to show direct United flights only. The journey takes around hour(s) min(s) – so you’ll be there before you know it. 

 

Flexible airline tickets for United flights from Ontario ONT to Seattle SEA 

Make sure you’re not out of pocket if plans change by choosing a flexible ticket with penalty-free amendment and cancellation options. Use our ‘no change fee’ filter to see which flights have this option.  

 

There are a lot of reasons to book your flights to Seattle SEA from  Ontario ONT with United on Travelocity 

At Travelocity our vast and up-to-the-minute inventory puts all of our best flight deals in one place. So, whether you’re traveling on business or jetting off with friends and family, you can trust Travelocity to get you there.

United Airports
Hop on a(n) United flight today by flying to many destinations out of these domestic and international airports:
Airport code
Country
Airport name
Number of flights
ORDUSAO'Hare Intl.227
DENUSADenver Intl.226
IAHUSAGeorge Bush Intercontinental136
IADUSAWashington Dulles Intl.100
SFOUSASan Francisco Intl.64
LAXUSALos Angeles Intl.23
EWRUSALiberty Intl.20
FRADEUFrankfurt Intl.19
NRTJPNNarita Intl.19
PEKCHNCapital Intl.16

Travelers ❤️ these 🏨 after their flight to Seattle

Red Roof Inn Seattle Airport - SEATAC
Red Roof Inn Seattle Airport - SEATAC
2 out of 5
16838 International Boulevard, SeaTac, WA
A gym, self parking, and laundry facilities are featured at this hotel. Guests will appreciate perks like free WiFi and a free airport shuttle. There's a safe ...
8/10 Very Good! (2,845 reviews)
"Good value for your dollar. Clean with Comfortable bed & good shuttle."

Reviewed on Apr 14, 2024

Red Roof Inn Seattle Airport - SEATAC
Country Inn & Suites by Radisson, Seattle-Tacoma International Airport, WA
Country Inn & Suites by Radisson, Seattle-Tacoma International Airport, WA
3 out of 5
3100 South 192nd Street, SeaTac, WA
This hotel features an indoor pool and a gym. Traveling on business? Take advantage of the 24-hour business center, free WiFi in public areas, and free airport ...
8.8/10 Excellent! (4,536 reviews)
"The bathroom was updated and modern, it had all the amenities and accessories needed in the room. The bed was comfortable which is important and I was able to use it for three nights no complaints. There is an elevator although quite slow. On busy nights it may be harder to find a parking space. ..."

Reviewed on Apr 15, 2024

Country Inn & Suites by Radisson, Seattle-Tacoma International Airport, WA
Coast Gateway Hotel
Coast Gateway Hotel
3.5 out of 5
18415 International Blvd, SeaTac, WA
This hotel features a restaurant, a gym, and a bar/lounge. Traveling on business? Take advantage of the 24-hour business center, free WiFi in public areas, and ...
9.2/10 Wonderful! (5,349 reviews)
"Really nice people and room"

Reviewed on Apr 14, 2024

Coast Gateway Hotel
Lowest nightly price found within the past 24 hours based on a 1 night stay for 2 adults. Prices and availability subject to change. Additional terms may apply.
*Price based on the lowest price found within past 24 hours and based upon one night stay for two adults over the next thirty days. Prices and availability subject to change. Additional terms may apply.