The cheapest times to fly from SDY to ONT are

  • January 1st to May 6th (except the weeks of February 12th, February 26th, and March 19th)
  • October 15th to May 6th (except the weeks of November 19th, November 26th, December 17th, December 24th, February 12th, February 26th, and March 19th)

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from SDY to ONT is late January. Prices can be as high as $749 for Sunday flights during early to mid August, or as low as $346 for Tuesday flights around late January.


When to Fly to Ontario

Flying from Sidney, MT (SDY) to Ontario, CA (ONT) will usually cost between $386 to $709 per person if booking more than four weeks in advance. On average the very cheapest time to fly is late January with an average ticket price of $380. Due to high demand the most expensive time to fly is early to mid August, with an average price of $712. Planning your trip to low-cost times can easily save you $332 on economy flights and even more on first-class flights. Generally, any price below $571 can be considered a good price for a round-trip SDY to ONT flight.

See below for a graph of average weekly prices for the SDY to ONT route. All prices are for round-trip tickets in USD.

SDY to ONT Flight Prices

Compared to other flights, the SDY to ONT flight is cheaper than the average and costs much less than the average flight leaving from Sidney. The average price per mile (for a direct flight) is $0.3, which is in the normal range for a flight.


Flight Prices by Day of the Week

Tuesday is usually the cheapest day to depart and return on this flight. Sundays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $116 (19%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Tuesday and returning a week later will cost an average of $504. Return trip prices are from the ONT to SDY flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from SDY to ONT can generally find a 2-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 3 hour 5 minutes may not be realistic.


Flight Hacking SDY to ONT

Flight hacking is when you book two tickets instead of a layover, sometimes with different airlines. You will need to either bring only a carry-on bag (highly recommended) or leave yourself plenty of time to go through security again. Flight hacking is completely allowed, but airlines don’t always tell you the cheapest way to get from SDY to ONT — but Champion Traveler does!

Hack #1: Billings, MT (SDY > BIL > ONT)

  • Price for both tickets: $433
  • Average savings: $139 (24.26%)

See SDY to BIL flights


Flight Questions Answered

Still have questions about flying from SDY to ONT? We’ve got answers.

Which airlines fly this route?

You can find 6 major airlines flying this route most often: Alaska, American, Cape Air, Delta, Frontier, United, and potentially more during busy seasons.

How far away is it from Ontario International Airport to Sidney Richland Regional Airport?

The distance between the two airports is roughly 1171 miles or 1885 kilometers.

How long does it take to fly from SDY to ONT?

The real-world flight time for a nonstop SDY to ONT flight is about 3 hour 5 minutes.

How many flights go between Sidney, MT and Ontario, CA?

It depends on the day of the week and the date, but a typical day might have around 19 available flights from SDY to ONT.


Airport Location Info


Departing Airport

Origination codeSDY
Origination airport nameSidney Richland Regional Airport
CitySidney, MT
Countrythe United States

Return Airport

Destination codeONT
Destination airport nameOntario International Airport
CityOntario, CA
Countrythe United States


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.