Cheap flights from St. Louis to Ontario (STL - ONT) from $110

Monday flights are generally found to be more expensive for flights from St. Louis to Ontario. This shouldn’t discourage you from searching, as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Ontario.

Travelers have found it’s best to book a flight 43 days in advance to save up to 30% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 43 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from St. Louis to Ontario 1-2 weeks in advance for as low as $409, or $511 for flights within the next 24 hours.

Our data shows that April tends to be the cheapest month to fly to Ontario from St. Louis. Users have commonly found prices around $381 for the month, but tickets can be as low as $152. Due to multiple factors, prepare for potentially higher prices in July.

It’s optimal to fly from St. Louis to Ontario in the evening. By choosing this option you can save up to 63% on the cost of your flight, compared to a flight in the morning.

Some of the carriers operating flights from Lambert-St Louis to Ontario that may be offering flexible cancellation policies are Frontier, American Airlines, and Delta. Our site will let you filter for all airlines offering greater flexibility due to COVID-19.

Yes, there are multiple flights from St. Louis to Ontario for under $200. The cheapest flight booked recently is on Frontier for just $200, but on average you can expect to pay $257.

Cheapflights has at least 3 direct flights from St. Louis to Ontario under $500. A good price for a nonstop flight from St. Louis to Ontario is less than $728.

There are currently 20+ open flights from St. Louis to Ontario within the next 7 days for less than $700.

This flight path from Lambert-St Louis to Ontario was viewed by 11 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

Frontier, at $200, was found to be the cheapest airline from St. Louis to Ontario. An alternate airline flying to your destination would be Undisclosed Carrier. Frontier is priced at 50% lower than the current average price of a flight leaving 3 months from now.

The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $110. However, be on the lookout for offers from Undisclosed Carrier and United Airlines, as they are both options that can get you from St. Louis to Ontario for a low price.

Before booking your flight from St. Louis to Ontario check out the most popular airlines for this route: American Airlines, Delta or Frontier.

Lambert-St Louis Airport is STL and Ontario Airport is ONT. These codes are created by the International Air Transport Association (IATA) and airlines use them to identify the departing and arrival airports in the flight routes they service.