Cheap Flight Tickets from Ontario (ONT) to Seattle (SEA), Starting at $211

Good to Know: Cheapest and Fastest ONT - SEA Flights

Useful information for finding best airline tickets from Ontario International to Seattle Tacoma International on your next trip.

Cheapest Round Trip Flight

$284

DL Delta Airlines • nonstop • 4h 17m

Aug 30 – Sep 06

The cheapest round trip flight from Ontario to Seattle (ONT-SEA-ONT) is currently $284

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Cheapest Direct Flight

$211

F9 Frontier Airlines • nonstop • 4h 5m

Aug 28

The cheapest nonstop flight from Ontario to Seattle (ONT-SEA) is currently $211

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Fastest Flight

4h 5m

The fastest nonstop flight from Ontario to Seattle (ONT-SEA) takes 4h 5m

Top Airlines Flying from Ontario to Seattle

Delta Airline, DL

Delta Airlines

Alaska Airlines -AS

Alaska Airlines

United Airlines, UA

United Airlines

American Airlines, AA

American Airlines

Latest Flight Deals from Ontario (ONT) to Seattle (SEA)

Compare and book low fare round-trip air tickets from Ontario to Seattle. Ideal for travelers with confirmed return itineraries.

Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
4h 17m
6:20 AM - 9:17 AM • nonstop
DL
Ontario → Seattle
4h 3m
9:59 AM - 12:42 PM • nonstop
$284
Delta Airlines
Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
10h 54m
5:05 PM - 11:59 PM • 1 stop
DL
Ontario → Seattle
4h 9m
6:15 PM - 9:04 PM • nonstop
$287
Delta Airlines
Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
11h 51m
9:43 AM - 4:54 PM • 1 stop
DL
Ontario → Seattle
4h 3m
9:59 AM - 12:42 PM • nonstop
$309
Delta Airlines
Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
4h 17m
6:20 AM - 9:17 AM • nonstop
DL
Ontario → Seattle
7h 13m
5:50 PM - 10:23 PM • 1 stop
$336
Delta Airlines
Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
8h 20m
5:05 PM - 10:05 PM • 1 stop
DL
Ontario → Seattle
7h 13m
5:50 PM - 10:23 PM • 1 stop
$342
Delta Airlines
Aug 30 - Sep 06, Economy
DL
Ontario → Seattle
11h 51m
9:43 AM - 4:54 PM • 1 stop
DL
Ontario → Seattle
7h 13m
5:50 PM - 10:23 PM • 1 stop
$373
Delta Airlines

Fly from Ontario to Seattle with the Best Airfare Deals on FareLeaders

Looking for a cheap last-minute deal or the best round-trip flight from Ontario to Seattle? Find the biggest savings on one-way and round-trip tickets right here.

FAQs on Ontario to Seattle Flights

What are the airports in Ontario?
ONT
What’s the most popular airline flying from ONT to SEA?
The most popular airline flying from Ontario to Seattle are
Can I fly from ONT to SEA non-stop?
Yes, you can fly ONT to SEA non-stop on
Which airlines fly nonstop between Ontario and Seattle?
The non-stop flights between Ontario and Seattle are .
What’s the earliest departure time from ONT to SEA Airport?
The earliest flight leaves ONT at 6:20 am and lands in SEA - Seattle Tacoma International
What are the airports in Seattle?
SEA
Can I make changes to my Ontario to Seattle flight tickets or cancel them on FareLeaders.com?
No. We are an airfare comparison site. All the tickets are booked by the travel agent offering the flight deal and any changes or cancellations to be made are directly done directly by them or the airlines.
Can I cancel my flight tickets from ONT to SEA?
Read the fare rules of the Ontario to Seattle air tickets booked. Some airlines allow you to cancel the tickets within a stipulated time period with a cancellation fee.
Which airline alliances offer flights from Ontario and Seattle?
operate flights between Ontario and Seattle
How long does a flight from Ontario to Seattle take?
It takes approximately 3 hour to fly non-stop from ONT to SEA, which is 956.13 miles by air.
Which airlines provide the cheapest flights from Ontario (ONT) to Seattle (SEA) ?
In the past couple of days, the cheapest tickets to SEA from ONT were found on DL : USD 373
Do I need a passport to fly between ONT and SEA?
No
What’s the latest departure time from ONT to SEA ?
The last flight leaves ONT at 6:01 pm

Ontario (ONT) to Seattle (SEA): Airport Information

Origin Airport Ontario International , Ontario, US
Destination Airport Seattle Tacoma International , Seattle, US
Distance 956 miles

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