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75 € Cheap Flights from Seattle / Tacoma International to Ontario International

Compare Seattle / Tacoma International to Ontario International flight deals

Find the cheapest month or even day of the year to fly to Ontario International

Book the best Ontario International fare with no extra fees

Flight deals from Seattle / Tacoma International to Ontario International

Looking for a cheap last-minute deal or the best return flight from Seattle / Tacoma International Airport to Ontario International Airport? If you want to travel next month, return fares start from 75 €. Find the lowest prices on one-way and return tickets right here.
Ontario.75 € per passenger.Departing Sat, 30 May, returning Tue, 9 Jun.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Sat, 30 May, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Tue, 9 Jun, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 75 €, select.
Ontario.75 € per passenger.Departing Mon, 1 Jun, returning Mon, 8 Jun.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Mon, 1 Jun, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Mon, 8 Jun, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 75 €, select.
Ontario.77 € per passenger.Departing Fri, 29 May, returning Sat, 30 May.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Fri, 29 May, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Sat, 30 May, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 77 €, select.
Ontario.158 € per passenger.Departing Thu, 13 Aug, returning Thu, 20 Aug.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Thu, 13 Aug, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Thu, 20 Aug, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 158 €, select.
Ontario.171 € per passenger.Departing Wed, 29 Jul, returning Thu, 13 Aug.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Seattle / Tacoma International on Wed, 29 Jul, arriving in Ontario International.Inbound indirect flight with Frontier Airlines, departs from Ontario International on Thu, 13 Aug, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 171 €, select.
Ontario.174 € per passenger.Departing Wed, 1 Jul, returning Wed, 15 Jul.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Seattle / Tacoma International on Wed, 1 Jul, arriving in Ontario International.Inbound indirect flight with Frontier Airlines, departs from Ontario International on Wed, 15 Jul, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 174 €, select.
Ontario.187 € per passenger.Departing Thu, 27 Aug, returning Wed, 2 Sep.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Seattle / Tacoma International on Thu, 27 Aug, arriving in Ontario International.Inbound indirect flight with Frontier Airlines, departs from Ontario International on Wed, 2 Sep, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 187 €, select.
Ontario.189 € per passenger.Departing Tue, 1 Sep, returning Tue, 8 Sep.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Tue, 1 Sep, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Tue, 8 Sep, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 189 €, select.
Ontario.204 € per passenger.Departing Sat, 4 Jul, returning Wed, 8 Jul.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Sat, 4 Jul, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Wed, 8 Jul, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 204 €, select.
Ontario.208 € per passenger.Departing Sun, 28 Jun, returning Fri, 3 Jul.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Sun, 28 Jun, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Fri, 3 Jul, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 208 €, select.
Ontario.208 € per passenger.Departing Thu, 27 Aug, returning Wed, 2 Sep.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Thu, 27 Aug, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Wed, 2 Sep, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 208 €, select.
Ontario.210 € per passenger.Departing Thu, 30 Apr, returning Mon, 4 May.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Seattle / Tacoma International on Thu, 30 Apr, arriving in Ontario International.Inbound indirect flight with Frontier Airlines, departs from Ontario International on Mon, 4 May, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 210 €, select.
Ontario.236 € per passenger.Departing Wed, 27 May, returning Tue, 10 Nov.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Wed, 27 May, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Tue, 10 Nov, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 236 €, select.
Ontario.238 € per passenger.Departing Fri, 19 Jun, returning Wed, 26 Aug.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Fri, 19 Jun, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Wed, 26 Aug, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 238 €, select.
Ontario.239 € per passenger.Departing Fri, 4 Sep, returning Mon, 7 Sep.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Seattle / Tacoma International on Fri, 4 Sep, arriving in Ontario International.Inbound direct flight with Frontier Airlines departs from Ontario International on Mon, 7 Sep, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 239 €, select.
Ontario.240 € per passenger.Departing Fri, 29 May, returning Mon, 13 Jul.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Fri, 29 May, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Mon, 13 Jul, arriving in Seattle / Tacoma International.Price includes taxes and charges.From 240 €, select.

Find the cheapest month to fly from Seattle / Tacoma International to Ontario International

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Seattle / Tacoma International to Ontario International flights are currently cheapest in June.
May
from 77 €
Jun
from 75 €
Jul
from 174 €
Aug
from 158 €
Sep
from 189 €
Oct
from 269 €
Nov
from 270 €
Dec
from 344 €
Jan
Find prices
Feb
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Mar
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Apr
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Direct flights from Seattle / Tacoma International to Ontario International

Seattle / Tacoma International to Ontario International: Alternative routes

Compare routes from Seattle / Tacoma International to Ontario below. You may find an airport to fly into that's cheaper, faster, or easier than Ontario International.

Ontario International

4km from central Ontario
Closest
from 75 €
Search flights

San Bernardino Norton AFB

39km from central Ontario
from 593 €
Search flights

Santa Ana John Wayne

48km from central Ontario
from 153 €
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Long Beach Municipal

54km from central Ontario
from 133 €
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Hawthorne

65km from central Ontario
from 465 €
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Burbank

67km from central Ontario
from 132 €
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Los Angeles International

71km from central Ontario
Cheapest
from 61 €
Search flights

Seattle to Ontario: Flight information

The things to know before you go.
Cheapest flight found75 €
Cheapest month to flyJune
Average flight time2 hrs, 46 mins
Most popular airlineAlaska Airlines
Average flights per week146

Finding cheap flights from Seattle / Tacoma International to Ontario International: Frequently asked questions

The best price we found for a return flight from Seattle / Tacoma International to Ontario International is 75 €. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
2 hours and 46 minutes is the average flight time from Seattle / Tacoma International to Ontario International.
Alaska Airlines, WestJet and Qatar Airways fly direct from Seattle / Tacoma International to Ontario International.
As of May 2026, there are 147 flights per week flying from Seattle / Tacoma International to Ontario International.
The cheapest month to fly from Seattle / Tacoma International to Ontario International is usually June.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Seattle / Tacoma International Airport to Ontario International Airport on Monday, 1 June 2026.
Yes – the average flight time is 2 hours and 46 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Ontario International but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Ontario is around 40 days in advance, so don’t leave your flight to the last minute.
Currently, Frontier Airlines offers the cheapest flight tickets to Ontario International.

Flying from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT): what you need to know

  • The average length of a direct flight from Seattle-Tacoma International Airport to Ontario International Airport is 2 hours 40 minutes.

  • Seattle and Ontario are both in the UTC-7 timezone. This means you won't need to account for any time differences.

  • Flights from SEA to ONT start at 06:30 — the earliest with Alaska Airlines. The last service of the day is at 21:31 with Alaska Airlines. In total, there are 67 weekly Seattle-Tacoma International Airport to Ontario International Airport flights.

  • Your SEA to ONT flight won't wait if you're late, so get to the airport on time. Arrive up to one hour in advance for domestic flights and two hours ahead when you're flying internationally.

  • During popular months such as July, you'll want to get to the airport even earlier. Arrive two hours before domestic departures and four hours ahead for international flights whenever you're travelling during a high season in general.

  • With direct flights from Seattle-Tacoma International Airport to Ontario International Airport operated by a number of airlines, flying to Ontario (and then other parts of United States) is easy. Here's who you can travel nonstop with:

  • The airline most travellers prefer to fly with on this route is Alaska Airlines.

  • Delta Air Lines leads the way as the most punctual carrier for SEA to ONT flights, with 89.93% of services reaching their destination on schedule.

  • If you want to break up your flight, just uncheck 'Direct flights only' when searching for your ticket from Seattle-Tacoma International Airport to Ontario International Airport. Here are the top stopovers between SEA and ONT:

    • Sacramento International Airport

    • Portland International Airport

    • Metropolitan Oakland International Airport

How to find the cheapest flights from Seattle-Tacoma International Airport (SEA) to Ontario International Airport (ONT)

  • Right now, 37 € is the lowest price we've found for a one-way Seattle-Tacoma International Airport to Ontario International Airport flight. The best price for a return plane ticket is 75 €. Bear in mind that fares may change due to demand at the time of booking.

  • To get cheap tickets from SEA to ONT, book your journey six months before your planned departure.

  • The cheapest month for flights from Seattle-Tacoma International Airport to Ontario International Airport is May. Use the 'Whole month' tool to find the lowest prices if you have flexible dates.

  • There's no need to check back in every day to find out if fares have gone down when you create a Price Alert. We'll update you as soon as there's a change in price on cheap flights from SEA to ONT.

  • Tailor your flights using filters. Select your ideal arrival and departure times, total journey duration and airlines. You can also sort results by 'Best,' 'Fastest' or 'Cheapest' flights from Seattle-Tacoma International Airport to Ontario International Airport.

Handy information about Seattle-Tacoma International Airport (SEA)

  • 81.27% of flights departing from Seattle-Tacoma International Airport arrive at their destination on schedule. Given its impressive on-time stats, you're unlikely to be delayed when jetting out of SEA.

  • Seattle-Tacoma International Airport is about 23 kilometres from central Seattle. If you're ride-sharing, catching a cab or driving from the centre, it'll take you 20 minutes or so to get there, depending on the traffic.

  • You can expect a trip time of about 55 minutes on public transport.

  • Get your holiday off to a relaxed start by staying near SEA. Whether you're catching an early flight from Seattle-Tacoma International Airport to Ontario International Airport or just don't like being rushed, these hotels are perfect:

Arriving at Ontario International Airport (ONT)

Getting from Ontario International Airport (ONT) to central Ontario

  • The street address for ONT is 2900 E. Airport Drive.

  • Ontario International Airport is approximately 6 kilometres from central Ontario. The drive time takes about 10 minutes.

  • If you're taking public transport, expect a journey time of about 1 hour 30 minutes.

When to fly to Ontario International Airport (ONT)

  • It's time to work out your trip dates for your flight from Seattle-Tacoma International Airport to Ontario International Airport. August is the busiest month to head to Ontario. If you want a more laid-back vibe, go in May.

  • Book your flight from Seattle-Tacoma International Airport to Ontario International Airport for August if you want to explore Ontario during its warmest month. You can expect temperatures of between 15ºC (59ºF) and 35ºC (95ºF).

  • January sees average temperatures of between 4ºC (39ºF) and 23ºC (73ºF). Search for cheap tickets from SEA to ONT sometime around then if you want to travel when it's cooler.

Explore more of United States

  • Ontario has loads to offer, but there are so many other parts of United States waiting to be explored. Around 56 kilometres west of Ontario, a visit to Los Angeles will keep you busy. Check out popular attractions like Griffith Observatory, The Broad and La Brea Tar Pits & Museum.

  • If you're interested in discovering another well-known destination in United States, consider San Diego, about 153 kilometres south of Ontario. San Diego Zoo, USS Midway Museum and SeaWorld San Diego are highlights.

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.