Find Cheap Flights from Seattle to Ontario (SEA - LAX)

Flights overview

Useful information for finding cheap flights from Seattle to Ontario and booking your next trip

Cheapest round-trip flights	$88	Frontier Nonstop 3 hr Fri, Jun 5 — Sun, Jun 7	The cheapest round-trip flight from Seattle to Ontario is currently $88
Cheapest one-way flight	$44	Frontier Nonstop 3 hr Thu, May 28	The cheapest one-way flight from Seattle to Ontario is currently $44
Last-minute weekend getaway	$345	Frontier 1 stop 15 hr Thu, May 7 — Sun, May 10	The cheapest last-minute weekend getaway from Seattle to Ontario is currently $345
Cheapest business class flights	$296	Frontier Nonstop 3 hr Fri, Jun 5 — Sun, Jun 7	The cheapest business class round-trip flight from Seattle to Ontario is currently $296

Fastest flight	2 hr 35 min	The fastest nonstop flight from Seattle to Ontario takes 2 hr 35 min
Nonstop flights	Every day	There are direct flights on this route every day.

When is the cheapest time to fly?

The cheapest month to fly from Seattle to Ontario is typically January. The most expensive month to fly is typically March.

January Cheapest	Typical prices: $105–300
March Most expensive	Typical prices: $175–375

Popular airlines from Seattle to Ontario

Delta

Nonstop

from $257

Typical price: $185–425

28 weekly nonstop flights

SEA - ONT Every day

108 weekly connecting flights

SEA - ONT Every day
Alaska

Nonstop

from $227

Typical price: $180–390

25 weekly nonstop flights

SEA - ONT Every day

222 weekly connecting flights

SEA - ONT Every day
Southwest

from $227

Typical price: $195–405

535 weekly connecting flights

SEA - ONT Every day
United

from $324

Typical price: $215–510

151 weekly connecting flights

SEA - ONT Every day
American

from $405

Typical price: $300–620

143 weekly connecting flights

SEA - ONT Every day
Frontier

from $88

Typical price: $140–305

28 weekly connecting flights

SEA - ONT Every day

Popular airports near Seattle

Seattle-Tacoma International Airport (SEA)

Seattle United States 18 min 11 mi
Portland International Airport (PDX)

Portland United States 2 hr 44 min 140 mi
Paine Field (PAE)

Everett United States 31 min 21 mi
King County International Airport - Boeing Field (BFI)

Seattle United States 11 min 5 mi

Popular airports near Ontario

Ontario International Airport (ONT)

Ontario United States 11 min 2 mi
Los Angeles International Airport (LAX)

Los Angeles United States 1 hr 7 min 44 mi
Tijuana International Airport (TIJ)

Tijuana Mexico 2 hr 16 min 112 mi
San Diego International Airport (SAN)

San Diego United States 1 hr 50 min 95 mi

Frequently asked questions about flying from Seattle to Ontario

The cheapest flights from Seattle to Ontario are usually in January. Typical ticket prices in January range from $105 to $300.

The cheapest round-trip flight from Seattle to Ontario recently found on Google Flights was with Frontier from $88. The cheapest one-way flight was with Frontier from $44.

Some of the cheapest round-trip deals we found with different airlines:

The cheapest Delta flight from Seattle to Ontario is $257, flying from Jun 6 to Jun 7.
The cheapest Alaska flight from Seattle to Ontario is $227, flying from Jun 6 to Jun 8.
The cheapest Southwest flight from Seattle to Ontario is $227, flying from Jun 6 to Jun 7.
The cheapest United flight from Seattle to Ontario is $324, flying from May 30 to Jun 1.
The cheapest American flight from Seattle to Ontario is $405, flying from Jun 6 to Jun 8.
The cheapest Frontier flight from Seattle to Ontario is $88, flying from Jun 5 to Jun 7.

The cheapest round-trip flight from Seattle to Ontario starts at $88 from Fri, Jun 5 to Sun, Jun 7. The cheapest one-way flight starts at $44 and departs on Thu, May 28.

2 hr 35 min is the shortest flight time from Seattle to Ontario.

Ontario is a year-round destination, with mild to warm weather for much of the year. Summers (Jun–Aug) tend to be hot, while winters (Dec–Feb) are typically mild. There is a slightly higher chance of rain Jan–Apr. The Road to California (Jan) is a quilt show featuring quilting competitions, classes and exhibits. The city celebrates Independence Day (Jul 4) with a parade, picnic and fireworks display. The Route 66 Cruisin' Reunion (Sep) attracts vintage cars from around the country.

It's easy to use Google Flights to find the cheapest days to fly from Seattle to Ontario.
Just click the Departure label near the top of the page to open the calendar. Choose a start date and a return date to see how the round-trip fare changes on those specific days.
Adjust the trip type to see one-way fares. The cheapest available flights are highlighted and easy to spot. Once you settle on dates, click the Search button to see flight options and book the deal.

You can also turn on price tracking to get alerts if the price changes for a route or flight.

What counts as the best airline for your flights from Seattle to Ontario really depends on your individual needs. You may have a favorite carrier or a loyalty program you like, but price, convenience, and airports served also come into play. Flexibility and booking terms – Can you change flights if you want to stay longer or get a refund if you have to postpone your trip? – are also factors that help determine which airline is best to fly from Seattle to Ontario.

In terms of nonstop flights, Delta is the most popular. Delta offers 28 nonstop flights and 108 connecting flights per week. Delta flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .

In terms of flights, Southwest is the most popular. Southwest offers 535 connecting flights per week. Southwest flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .

Other popular airlines flying from Seattle to Ontario are:

Alaska offers 25 nonstop flights and 222 connecting flights per week. Alaska flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .
United offers 151 connecting flights per week. United flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .
American offers 143 connecting flights per week. American flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .
Frontier offers 28 connecting flights per week. Frontier flies from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT) .

The number of connecting flights refers to distinct flights with at least one stop between Seattle and Ontario.

The cheapest round-trip flight from Seattle to Ontario recently found on Google Flights was with Frontier from $88. The cheapest one-way flight was with Frontier from $44.

Some of the cheapest round-trip deals we found with different airlines:

The cheapest Delta flight from Seattle to Ontario is $257, flying from Jun 6 to Jun 7.
The cheapest Alaska flight from Seattle to Ontario is $227, flying from Jun 6 to Jun 8.
The cheapest Southwest flight from Seattle to Ontario is $227, flying from Jun 6 to Jun 7.
The cheapest United flight from Seattle to Ontario is $324, flying from May 30 to Jun 1.
The cheapest American flight from Seattle to Ontario is $405, flying from Jun 6 to Jun 8.
The cheapest Frontier flight from Seattle to Ontario is $88, flying from Jun 5 to Jun 7.

Delta and Alaska fly direct from Seattle to Ontario.

There are 28 Delta direct flights from Seattle to Ontario per week. Flights are available every day.
There are 25 Alaska direct flights from Seattle to Ontario per week. Flights are available every day.

Use the Stops filter while searching for flights, to see only nonstop options in your results.

The cheapest last-minute deal between Seattle and Ontario at price $345 is offered by Frontier from Thu, May 7 to Sun, May 10.

Delta and Alaska fly direct from Seattle to Ontario.

There are 28 Delta direct flights from Seattle to Ontario per week. Flights are available every day.
There are 25 Alaska direct flights from Seattle to Ontario per week. Flights are available every day.

Use the Stops filter while searching for flights, to see only nonstop options in your results.

There are direct flights from Seattle to Ontario on a daily basis.

The cheapest direct (nonstop) round-trip flights between Seattle and Ontario start at $88 from Fri, Jun 5 to Sun, Jun 7 with Frontier.

It's easy to find nonstop flights with Google Flights! Once you've searched for flights from Seattle to Ontario, just select the nonstop flights only option in the 'Stops’ filter in the search form and view all available direct flights and their prices.

The cheapest business class round-trip flights between Seattle and Ontario start at $296 from Fri, Jun 5 to Sun, Jun 7 with Frontier.

The cheapest economy class round-trip flights between Seattle and Ontario start at $88 from Fri, Jun 5 to Sun, Jun 7.

To book business class trips from Seattle to Ontario, look for the default Economy selection at the top, and change it to your desired cabin class such as Premium Economy, Business Class, or First Class. You can then select your departure and arrival dates, consider available options, and book your business travel.

You can also adjust the trip type to view one-way fares.

The best last-minute getaway deal for the next weekend between Seattle and Ontario starts at $345 from Thu, May 7 to Sun, May 10 with Frontier.

The cheapest last-minute deal between Seattle and Ontario at price $345 is offered by Frontier from Thu, May 7 to Sun, May 10.

To find last-minute flight deals from Seattle to Ontario, start by entering the city names, select the desired departure and return dates, and hit the Search button to view flight options.

You can check for last-minute flights for the same day or adjust the trip type to see one-way fares.