Cheap flights from Ontario to Seattle

Flights overview

Useful information for finding cheap flights from Ontario to Seattle and booking your next trip
Cheapest round-trip flights $88
Frontier Nonstop 4 hr Thu, May 28 — Mon, Jun 1
The cheapest round-trip flight from Ontario to Seattle is currently $88
Cheapest one-way flight $44
Frontier Nonstop 4 hr Sun, Jun 7
The cheapest one-way flight from Ontario to Seattle is currently $44
Last-minute weekend getaway $291
Frontier 1 stop 19 hr Thu, May 7 — Sun, May 10
The cheapest last-minute weekend getaway from Ontario to Seattle is currently $291
Cheapest business class flights $296
Frontier Nonstop 4 hr Thu, May 28 — Mon, Jun 1
The cheapest business class round-trip flight from Ontario to Seattle is currently $296
Fastest flight 2 hr 39 min The fastest nonstop flight from Ontario to Seattle takes 2 hr 39 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 Ontario to Seattle is typically January. The most expensive month to fly is typically July.
January
Cheapest
Typical prices: $115–280
July
Most expensive
Typical prices: $195–300

Popular airlines from Ontario to Seattle

  • Alaska
    Nonstop
    from $217
    Typical price: $185–390
    25 weekly nonstop flights
    ONT - SEA Every day
    308 weekly connecting flights
    ONT - SEA Every day
  • Delta
    Nonstop
    from $207
    Typical price: $185–410
    28 weekly nonstop flights
    ONT - SEA Every day
    91 weekly connecting flights
    ONT - SEA Every day
  • Southwest
    from $227
    Typical price: $195–400
    509 weekly connecting flights
    ONT - SEA Every day
  • United
    from $282
    Typical price: $215–495
    159 weekly connecting flights
    ONT - SEA Every day
  • American
    from $382
    Typical price: $305–600
    136 weekly connecting flights
    ONT - SEA Every day
  • Frontier
    from $88
    Typical price: $140–310
    25 weekly connecting flights
    ONT - SEA Every day

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

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

Frequently asked questions about flying from Ontario to Seattle

The cheapest flights from Ontario to Seattle are usually in January. Typical ticket prices in January range from $115 to $280.
The cheapest round-trip flight from Ontario to Seattle 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 Alaska flight from Ontario to Seattle is $217, flying from Jun 4 to Jun 7.
  • The cheapest Delta flight from Ontario to Seattle is $207, flying from May 30 to May 31.
  • The cheapest Southwest flight from Ontario to Seattle is $227, flying from Jun 6 to Jun 7.
  • The cheapest United flight from Ontario to Seattle is $282, flying from Jun 6 to Jun 7.
  • The cheapest American flight from Ontario to Seattle is $382, flying from May 30 to May 31.
  • The cheapest Frontier flight from Ontario to Seattle is $88, flying from May 28 to Jun 1.
The cheapest round-trip flight from Ontario to Seattle starts at $88 from Thu, May 28 to Mon, Jun 1. The cheapest one-way flight starts at $44 and departs on Sun, Jun 7.
2 hr 39 min is the shortest flight time from Ontario to Seattle.
Most visitors come May–Sep, a period encompassing events such as the Seattle International Film Festival (May); Seafair (Jul), a summer festival including boat races, marathons and parades; and Bumbershoot (Sep), an international music and arts festival. Rainy season is Nov–May, though rain is possible year-round.
It's easy to use Google Flights to find the cheapest days to fly from Ontario to Seattle.
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 Ontario to Seattle 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 Ontario to Seattle.

In terms of nonstop flights, Delta is the most popular. Delta offers 28 nonstop flights and 91 connecting flights per week. Delta flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .

In terms of flights, Southwest is the most popular. Southwest offers 509 connecting flights per week. Southwest flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .

Other popular airlines flying from Ontario to Seattle are:
  • Alaska offers 25 nonstop flights and 308 connecting flights per week. Alaska flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .
  • United offers 159 connecting flights per week. United flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .
  • American offers 136 connecting flights per week. American flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .
  • Frontier offers 25 connecting flights per week. Frontier flies from Ontario International Airport (ONT) to Seattle-Tacoma International Airport (SEA) .
The number of connecting flights refers to distinct flights with at least one stop between Ontario and Seattle.
The cheapest round-trip flight from Ontario to Seattle 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 Alaska flight from Ontario to Seattle is $217, flying from Jun 4 to Jun 7.
  • The cheapest Delta flight from Ontario to Seattle is $207, flying from May 30 to May 31.
  • The cheapest Southwest flight from Ontario to Seattle is $227, flying from Jun 6 to Jun 7.
  • The cheapest United flight from Ontario to Seattle is $282, flying from Jun 6 to Jun 7.
  • The cheapest American flight from Ontario to Seattle is $382, flying from May 30 to May 31.
  • The cheapest Frontier flight from Ontario to Seattle is $88, flying from May 28 to Jun 1.
Delta and Alaska fly direct from Ontario to Seattle.
  • There are 25 Alaska direct flights from Ontario to Seattle per week. Flights are available every day.
  • There are 28 Delta direct flights from Ontario to Seattle 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 Ontario and Seattle at price $291 is offered by Frontier from Thu, May 7 to Sun, May 10.
Delta and Alaska fly direct from Ontario to Seattle.
  • There are 25 Alaska direct flights from Ontario to Seattle per week. Flights are available every day.
  • There are 28 Delta direct flights from Ontario to Seattle 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 Ontario to Seattle on a daily basis.
The cheapest direct (nonstop) round-trip flights between Ontario and Seattle start at $88 from Thu, May 28 to Mon, Jun 1 with Frontier.
It's easy to find nonstop flights with Google Flights! Once you've searched for flights from Ontario to Seattle, 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 Ontario and Seattle start at $296 from Thu, May 28 to Mon, Jun 1 with Frontier.
The cheapest economy class round-trip flights between Ontario and Seattle start at $88 from Thu, May 28 to Mon, Jun 1.
To book business class trips from Ontario to Seattle, 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 Ontario and Seattle starts at $291 from Thu, May 7 to Sun, May 10 with Frontier.
The cheapest last-minute deal between Ontario and Seattle at price $291 is offered by Frontier from Thu, May 7 to Sun, May 10.
To find last-minute flight deals from Ontario to Seattle, 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.

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Popular trips from Ontario

  1. Las Vegas
    $56
    Jun 4 — Jun 8
    Nonstop 1 hr 11 min Frontier
  2. Boston
    $292
    Sep 19 — Sep 21
    1 stop 9 hr 48 min United
  3. Hong Kong
    $1,077
    Oct 30 — Nov 2
    1 stop 20 hr 45 min Cathay Pacific, STARLUX Airlines
  4. Seattle
    $88
    May 28 — Jun 1
    Nonstop 3 hr 1 min Frontier

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