$100 Cheap Flights from Ontario (ONT) to Santa Rosa (STS)

View $100 flight on Sat, May 24, 2025Opens in a new window

  • Plan, book, fly with confidence

  • trending down icon
    Be in the know
    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon
    Book smarter
    Save up to 30% on select hotels after you book a flight*
  • one key icon
    Earn twice
    Earn your airline miles on top of our OneKeyCash
    Learn about One Key
Find available prices by choosing your travel dates.

Cheap Flights from Ontario to Santa Rosa (ONT-STS)

Prices were available within the past 7 days and start at $100 for one-way flights and $199 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Sat, May 24 - Thu, May 29
ONT
Ontario
STS
Santa Rosa
$199 Roundtrip, found 20 hours ago
$199
Roundtrip
found 20 hours ago
Select American Airlines flight, departing Sat, May 24 from Ontario to Santa Rosa, returning Thu, May 29, priced at $199 found 20 hours ago
American Airlines
Sat, May 24 - Mon, May 26
ONT
Ontario
STS
Santa Rosa
$223 Roundtrip, just found
$223
Roundtrip
just found
Select American Airlines flight, departing Sat, May 24 from Ontario to Santa Rosa, returning Mon, May 26, priced at $223 just found
American Airlines
Fri, May 23 - Mon, May 26
ONT
Ontario
STS
Santa Rosa
$247 Roundtrip, just found
$247
Roundtrip
just found
Select American Airlines flight, departing Fri, May 23 from Ontario to Santa Rosa, returning Mon, May 26, priced at $247 just found
American Airlines
Wed, May 28 - Thu, May 29
ONT
Ontario
STS
Santa Rosa
$259 Roundtrip, found 1 hour ago
$259
Roundtrip
found 1 hour ago
Select American Airlines flight, departing Wed, May 28 from Ontario to Santa Rosa, returning Thu, May 29, priced at $259 found 1 hour ago
American Airlines
Tue, May 13 - Thu, May 15
ONT
Ontario
STS
Santa Rosa
$267 Roundtrip, found 1 hour ago
$267
Roundtrip
found 1 hour ago
Select American Airlines flight, departing Tue, May 13 from Ontario to Santa Rosa, returning Thu, May 15, priced at $267 found 1 hour ago
American Airlines
Sat, May 24 - Mon, May 26
ONT
Ontario
STS
Santa Rosa
$283 Roundtrip, just found
$283
Roundtrip
just found
Select American Airlines flight, departing Sat, May 24 from Ontario to Santa Rosa, returning Mon, May 26, priced at $283 just found
American Airlines
Fri, May 9 - Sun, May 11
ONT
Ontario
STS
Santa Rosa
$287 Roundtrip, found 4 hours ago
$287
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Fri, May 9 from Ontario to Santa Rosa, returning Sun, May 11, priced at $287 found 4 hours ago
Alaska Airlines
Tue, May 20 - Thu, May 22
ONT
Ontario
STS
Santa Rosa
$299 Roundtrip, found 1 day ago
$299
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Tue, May 20 from Ontario to Santa Rosa, returning Thu, May 22, priced at $299 found 1 day ago
American Airlines
Wed, May 7 - Wed, May 28
ONT
Ontario
STS
Santa Rosa
$303 Roundtrip, found 6 hours ago
$303
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Wed, May 7 from Ontario to Santa Rosa, returning Wed, May 28, priced at $303 found 6 hours ago
Alaska Airlines
Tue, May 20 - Thu, May 22
ONT
Ontario
STS
Santa Rosa
$304 Roundtrip, found 1 day ago
$304
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Tue, May 20 from Ontario to Santa Rosa, returning Thu, May 22, priced at $304 found 1 day ago

Frequently asked questions

How much does a flight from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS) cost?
Discover the latest flight deals from ONT to STS by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from ONT to STS?
The cheapest flights from ONT to STS are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS)?
Direct flights aren’t available from Ontario, CA (ONT-Los Angeles - Ontario Intl.) to Sonoma County Airport (STS). However, there are other airports that have nonstop flights. Board your plane at Los Angeles Intl. Airport (LAX) and travel straight to Santa Rosa without any detours.
What is the cheapest airline that flies from ONT to STS?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from ONT to STS. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS)?
Direct flights from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS) aren’t available daily, so you’ll have to take a flight with a layover. Explore your options with Expedia’s filters. Enter your travel dates and pick either “1 Stop” or “2+ Stops.”
What day of the week has the most flights from ONT to STS?
Usually you’ll find the largest variety of flight choices on a Friday. Tuesdays are often the quietest.* However, this can vary depending on the season, airline and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS)?
To reach Sonoma County Airport (STS) on schedule, book a flight that leaves from Los Angeles - Ontario Intl. Airport (ONT) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
What airports do you fly into for Santa Rosa from Los Angeles - Ontario Intl. Airport (ONT)?
Catch a direct flight from Los Angeles - Ontario Intl. Airport (ONT) to Santa Rosa and arrive at San Francisco Intl. Airport (SFO). Another convenient entry point into this city is Oakland Intl. Airport (OAK).
Is it cheaper to buy a plane ticket from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS) last-minute?
Last-minute fares from ONT to STS are generally more expensive. To lock in the lowest rates, start looking for flights ahead of time. That said, if you’re flexible with your travel dates, you may score a cheap fare right before your trip.
Is it cheaper to book an ONT to STS flight and hotel package?
You can save money by booking an ONT to STS flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it’s easy to manage it all in one convenient place. Once you’ve selected your preferred flights and accommodations, you can add extras like tours, activities and car rentals.
Can I cancel or change the date of my flight from Los Angeles - Ontario Intl. Airport (ONT) to Sonoma County Airport (STS)?
In most cases, you can cancel or modify your ONT to STS flight. However, there may be additional fees, especially if you made your booking more than 24 hours ago. Double-check your itinerary for the airline’s policies and fees on flight changes, or if you need further details, visit our Customer Service portal.
*Available to One Key members.