Cheap Flight Tickets from Seattle (SEA) to Ontario (ONT), Starting at $191

Good to Know: Cheapest and Fastest SEA - ONT Flights

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

Cheapest Round Trip Flight

$350

F9 Frontier Airlines • 1 stop • 19h 10m

Aug 15 – Aug 17

The cheapest round trip flight from Seattle to Ontario (SEA-ONT-SEA) is currently $350

🔍 Search Flights

Cheapest One way Flight

$191

F9 Frontier Airlines • 1 stop • 24h 18m

Aug 03

The cheapest one way flight from Seattle to Ontario (SEA-ONT) is currently $191

🔍 Search Flights

Cheapest Direct Flight

$278

F9 Frontier Airlines • nonstop • 4h 15m

Aug 15

The cheapest nonstop flight from Seattle to Ontario (SEA-ONT) is currently $278

🔍 Search Flights

Fastest Flight

4h 1m

The fastest nonstop flight from Seattle to Ontario (SEA-ONT) takes 4h 1m

Top Airlines Flying from Seattle to Ontario

Southwest Airlines-WN

Southwest Airlines

Delta Airline, DL

Delta Airlines

United Airlines, UA

United Airlines

Alaska Airlines -AS

Alaska Airlines

American Airlines, AA

American Airlines

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

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

Aug 15 - Aug 17, Economy
F9
Seattle → Ontario
19h 10m
8:13 PM - 8:03 AM • 1 stop
F9
Seattle → Ontario
11h 57m
6:00 AM - 1:17 PM • 1 stop
$350
Frontier Airlines
Aug 15 - Aug 17, Economy
DL
Seattle → Ontario
4h 15m
7:50 PM - 10:45 PM • nonstop
DL
Seattle → Ontario
4h 4m
9:00 PM - 11:44 PM • nonstop
$487
Delta Airlines
Aug 15 - Aug 17, Economy
AS
Seattle → Ontario
7h 33m
6:59 PM - 11:52 PM • 1 stop
AS
Seattle → Ontario
9h 5m
4:25 PM - 10:10 PM • 1 stop
$497
Alaska Airlines
Aug 15 - Aug 17, Economy
WN
Seattle → Ontario
6h 50m
1:50 PM - 6:00 PM • 1 stop
WN
Seattle → Ontario
6h 40m
2:50 PM - 6:50 PM • 1 stop
$506
Southwest Airlines
Aug 15 - Aug 15, Economy
AS
Seattle → Ontario
4h 4m
10:25 AM - 1:09 PM • nonstop
AS
Seattle → Ontario
4h 7m
5:14 PM - 8:01 PM • nonstop
$677
Alaska Airlines
Aug 15 - Aug 15, Economy
AS
Seattle → Ontario
10h 38m
10:14 AM - 4:52 PM • 1 stop
AS
Seattle → Ontario
24h 11m
7:34 PM - 10:25 AM • 1 stop
$744
Alaska Airlines

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

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

FAQs on Seattle to Ontario Flights

What are the airports in Seattle?
SEA
What’s the most popular airline flying from SEA to ONT?
The most popular airline flying from Seattle to Ontario are
Can I fly from SEA to ONT non-stop?
Yes, you can fly SEA to ONT non-stop on
Which airlines fly nonstop between Seattle and Ontario?
The non-stop flights between Seattle and Ontario are .
What’s the earliest departure time from SEA to ONT Airport?
The earliest flight leaves SEA at 6:15 am and lands in ONT - Ontario International
What are the airports in Ontario?
ONT
Can I make changes to my Seattle to Ontario 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 SEA to ONT?
Read the fare rules of the Seattle to Ontario 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 Seattle and Ontario?
operate flights between Seattle and Ontario
How long does a flight from Seattle to Ontario take?
It takes approximately 3 hour to fly non-stop from SEA to ONT, which is 956.13 miles by air.
Which airlines provide the cheapest flights from Seattle (SEA) to Ontario (ONT) ?
In the past couple of days, the cheapest tickets to ONT from SEA were found on AS : USD 573
Do I need a passport to fly between SEA and ONT?
No
What’s the latest departure time from SEA to ONT ?
The last flight leaves SEA at 8:13 pm

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

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

More Flight Options for Seattle (SEA) and Ontario (ONT)

Why Fareleaders for SEA to ONT Plane Tickets

Lowest Prices
Lowest Prices
Uncover the best deals on Seattle to Ontario flights by comparing fares from hundreds of airlines and agencies.
New Deals
New Deals Everyday
Get the best prices on SEA to ONT flights—we update our fares daily so you never miss a saving.
Best Travel Options
No Service Fees
Compare hundreds of Seattle to Ontario flights and secure the best deals—we never add any service fees.
Get Fare Drop Alert
Be the first to know when fares drop for the Seattle (SEA) to Ontario (ONT)
Terms and Conditions*