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Cheap flight tickets from Santa Rosa to Ontario International

Compare Santa Rosa 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 Santa Rosa to Ontario International

Looking for a cheap last-minute deal or the best return flight from Santa Rosa to Ontario International? Find the lowest prices on one-way and return tickets right here.
Ontario.RM1,002 per passenger.Departing Wed, 19 Aug, returning Wed, 26 Aug.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Wed, 19 Aug, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Wed, 26 Aug, arriving in Santa Rosa.Price includes taxes and charges.From RM1,002, select.
Ontario.RM1,119 per passenger.Departing Sat, 18 Apr, returning Wed, 22 Apr.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Sat, 18 Apr, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Wed, 22 Apr, arriving in Santa Rosa.Price includes taxes and charges.From RM1,119, select.
Ontario.RM1,119 per passenger.Departing Thu, 9 Apr, returning Thu, 7 May.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Thu, 9 Apr, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Thu, 7 May, arriving in Santa Rosa.Price includes taxes and charges.From RM1,119, select.
Ontario.RM1,201 per passenger.Departing Wed, 1 Jul, returning Tue, 7 Jul.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Wed, 1 Jul, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Tue, 7 Jul, arriving in Santa Rosa.Price includes taxes and charges.From RM1,201, select.
Ontario.RM1,286 per passenger.Departing Mon, 9 Mar, returning Thu, 12 Mar.Return flight with Alaska Airlines and Frontier Airlines.Outbound indirect flight with Alaska Airlines, departs from Santa Rosa on Mon, 9 Mar, arriving in Ontario International.Inbound indirect flight with Frontier Airlines, departs from Ontario International on Thu, 12 Mar, arriving in Santa Rosa.Price includes taxes and charges.From RM1,286, select.
Ontario.RM1,433 per passenger.Departing Mon, 31 Aug, returning Thu, 3 Sep.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Mon, 31 Aug, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Thu, 3 Sep, arriving in Santa Rosa.Price includes taxes and charges.From RM1,433, select.
Ontario.RM1,503 per passenger.Departing Tue, 30 Jun, returning Mon, 6 Jul.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Tue, 30 Jun, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Mon, 6 Jul, arriving in Santa Rosa.Price includes taxes and charges.From RM1,503, select.
Ontario.RM1,585 per passenger.Departing Fri, 8 May, returning Sun, 10 May.Return flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Santa Rosa on Fri, 8 May, arriving in Ontario International.Inbound indirect flight with Southwest Airlines, departs from Ontario International on Sun, 10 May, arriving in Santa Rosa.Price includes taxes and charges.From RM1,585, select.

Find the cheapest month to fly from Santa Rosa to Ontario International

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Santa Rosa to Ontario International flights are currently cheapest in August.
Feb
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Mar
from RM1,286
Apr
from RM1,119
May
from RM1,585
Jun
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Jul
from RM1,201
Aug
from RM1,002
Sep
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Oct
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Nov
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Dec
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Jan
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Direct flights from Santa Rosa to Ontario International

Santa Rosa to Ontario International: Alternative routes

Compare routes from Santa Rosa 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 RM1,002
Search flights

San Bernardino Norton AFB

39km from central Ontario
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Santa Ana John Wayne

48km from central Ontario
from RM1,031
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Long Beach Municipal

54km from central Ontario
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Hawthorne

65km from central Ontario
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Burbank

67km from central Ontario
from RM611
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Los Angeles International

71km from central Ontario
Cheapest
from RM607
Search flights

Santa Rosa to Ontario: Flight information

The things to know before you go.
Cheapest flight foundRM1,002
Cheapest month to flyAugust
Average flight time1 hr, 28 mins
Most popular airlineAlaska Airlines
Average flights per week16

Finding cheap flights from Santa Rosa to Ontario International: Frequently asked questions

The best price we found for a return flight from Santa Rosa to Ontario International is RM1,002. 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.
1 hour and 28 minutes is the average flight time from Santa Rosa to Ontario International.
Alaska Airlines, SkyWest Airlines and Horizon Air fly direct from Santa Rosa to Ontario International.
As of February 2026, there are 16 flights per week flying from Santa Rosa to Ontario International.
The cheapest month to fly from Santa Rosa to Ontario International is usually August.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Santa Rosa Airport to Ontario International Airport on Wednesday, 19 August 2026.
Yes – the average flight time is 1 hour and 28 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, Southwest Airlines offers the cheapest flight tickets to Ontario International.

Travelling from Sonoma County Airport (STS) to Ontario International Airport (ONT): what you need to know

  • Santa Rosa and Ontario share the same timezone, UTC-7.

  • Arrive at the airport on time so you don't miss your STS to ONT flight. Be there at least two hours ahead for international flights and an hour early for domestic departures to avoid the stress of rushing.

  • During popular months such as October, it's best to get to the airport earlier. Plan to arrive two hours before domestic departures and four hours ahead for international flights when you fly during a peak period in general.

  • If you'd like to discover a new city along the way, search for a flight with a stopover. To see your options for tickets from Sonoma County Airport to Ontario International Airport, deselect 'Direct flights only.' Phoenix Sky Harbour International Airport is a popular stop between STS and ONT.

How to find the cheapest flights from Sonoma County Airport (STS) to Ontario International Airport (ONT)

  • Currently, RM403 is the cheapest price we've seen for a one-way Sonoma County Airport to Ontario International Airport flight. The best price for a return ticket is RM1,002. Keep in mind that fares can change due to demand at the time of booking.

  • Don't wait until the last moment. You're more likely to find cheap tickets from STS to ONT if you book early. Airlines often offer some excellent early bird rates.

  • If you can be flexible with your trip dates, try using the 'Whole month' tool. It'll show you the cheapest price in each month when searching for a flight from Sonoma County Airport to Ontario International Airport.

  • Getting your hands on cheap flights from STS to ONT is easy with Price Alerts. All you need to do is create one of these automatic alerts and we'll notify you when a lower fare pops up.

  • Choose your preferred arrival and departure times, airlines and number of stops with the filters. Alternatively, sort your results by 'Cheapest' to see the best deals on flights from Sonoma County Airport to Ontario International Airport.

Handy information about Sonoma County Airport (STS)

  • You'll find STS at 2200 Airport Boulevard.

  • Of all flights leaving Sonoma County Airport, 73.45% arrive as scheduled at their destination.

  • Sonoma County Airport is about 13 kilometres from central Santa Rosa. If you're driving, ride-sharing or catching a cab from the centre, it'll take you 15 minutes or so to arrive, depending on the traffic.

  • The trip when using public transport will take about 35 minutes.

  • Catching an early flight from Sonoma County Airport to Ontario International Airport? Avoid the last-minute rush to the terminal (and sneak in some extra precious sleep) by picking one of these stays close to STS:

Arriving at Ontario International Airport (ONT)

Getting from Ontario International Airport (ONT) to central Ontario

  • You'll find ONT at 2900 E. Airport Drive.

  • Ontario International Airport is roughly 6 kilometres from the centre of Ontario. The drive time takes about 10 minutes.

  • Getting to the centre by public transport takes about 1 hour 30 minutes.

When to fly to Ontario International Airport (ONT)

  • It's time to plan your dates for your flight from Sonoma County Airport to Ontario International Airport. August is the most popular month to head to Ontario. If you'd like a more laid-back vibe, go in May.

  • When booking your flight from Sonoma County Airport to Ontario International Airport, consider the kind of weather you enjoy. August is the warmest month in Ontario, with temperatures ranging from 15ºC (59ºF) to 35ºC (95ºF).

  • Look for cheap tickets from STS to ONT in January if you'd rather travel during cooler conditions. Temperatures are at their lowest then, ranging between 4ºC (39ºF) and 23ºC (73ºF) on average.

Explore more of United States

  • Ontario is always a good idea, but there are so many other parts of United States waiting to be discovered. About 56 kilometres west of Ontario, a trip to Los Angeles will fill your itinerary to the brim. Start with leading sights like Griffith Observatory, The Broad and La Brea Tar Pits & Museum.

  • If you're interested in discovering another side of United States, head for San Diego, about 153 kilometres south of Ontario. San Diego Zoo, USS Midway Museum and SeaWorld San Diego are key reasons to visit.

Plan the rest of your trip from Santa Rosa to Ontario

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