Seattle to Ontario flights
Round trip · Economy · Prices per person in USD
Prices updated
Prices are low right now
$175 is $116 (40%) below the usual $291 for Seattle → Ontario.
Buy now or wait? We're still learning this route. We have 1 day of prices so far and need about a week to say whether to book or wait.
Not ready to book? Get an email when Seattle → Ontario drops below your price.Cheapest round trip by month
Lowest fare found per departure month| Month | Cheapest round trip |
|---|---|
| September 2026 | $297 |
| October 2026 | $175 (cheapest month) |
| November 2026 | $272 |
| December 2026 | $310 |
| January 2027 | No fares found yet |
| February 2027 | No fares found yet |
| March 2027 | No fares found yet |
| April 2027 | $383 |
Cheapest dates in the next 4 months
Round trip, per person-
Oct 24 – 26 2 nights · leave Sat$175 −40% vs usual$175 −40% vs usual Book
Frontier Airlines 1 stop · 5h 11m -
Nov 29 – Dec 2 3 nights · leave Sun$272 −7% vs usual$272 −7% vs usual Book
Frontier Airlines 1 stop · 3h 53m
-
Nov 17 – 20 3 nights · leave Tue$273 −6% vs usual$273 −6% vs usual Book
Southwest Airlines Nonstop · 4h 15m -
Dec 13 – 18 5 nights · leave Sun$310 +7% vs usual$310 +7% vs usual Book
Frontier Airlines 1 stop · 3h 44m
-
Oct 14 – 21 7 nights · leave Wed$311 +7% vs usual$311 +7% vs usual Book
Alaska Airlines Nonstop · 2h 32m -
Dec 18 – 21 3 nights · leave Fri$331 +14% vs usual$331 +14% vs usual Book
Frontier Airlines 1 stop · 2h 48m
-
Oct 7 – 11 4 nights · leave Wed$370 +27% vs usual$370 +27% vs usual Book
Frontier Airlines Nonstop · 2h 52m
-
Oct 4 – 6 2 nights · leave Sun$469 +61% vs usual$469 +61% vs usual Book
Frontier Airlines Nonstop · 2h 52m
Prices change often. The booking site shows the final price before you pay. Other dates? Set an alert
Plan the rest of your trip
Ontario · Oct 24 – 26Travel insurance · EKTA Airport transfer · Kiwitaxi
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Good to know
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Seattle to Ontario: questions
How much is a flight from Seattle to Ontario?
The cheapest round trip we have found right now is $175, leaving October 24 and returning October 26. The usual price on this route is about $291, so this fare is 40% less. Prices are per person, economy, in USD.
What is the cheapest month to fly from Seattle to Ontario?
October 2026, with round trips from $175. The most expensive month in our data is April (from $383). Based on the 5 months ahead we have prices for.
Are there nonstop flights from Seattle to Ontario?
Yes. Nonstop from $273 round trip. 50% of the 8 date combinations we track are nonstop.
About this route
We track round-trip economy fares from Seattle (United States) to Ontario (United States) using Travelpayouts / Aviasales data. The cheapest round trip we've found is $175, departing October 24 and returning October 26, about 40% below the usual $291. Right now we're following 8 upcoming date combinations on this route. The cheapest month to fly in our data is October, from $175. Prices are per person and were correct when found; the final price is set by the airline or booking site when you book.