Cheap flights from Atlanta to Los Angeles from $63

In general, April is the cheapest month to fly from Atlanta to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $401. If you aren’t able to travel during the month of April, then book flights to Ontario from Atlanta during October instead. Flights to Ontario in October, while not as cheap as those in April, still average around $407.

The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $469. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Atlanta to Ontario for around $629.

In the afternoon is the cheapest time of day to fly from Atlanta to Ontario when you can find flight prices for as low as $539. Flying to Ontario in the afternoon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $569 on average. Flights to Ontario from Atlanta in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

Fly from Atlanta Hartsfield-Jackson to Ontario for the best Atlanta Hartsfield-Jackson - Ontario flight prices

You are more likely to see cheaper flights to Ontario from Atlanta when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $466 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Atlanta for as low as $429 on momondo.

There are 4 cabin classes available to choose from on Atlanta to Ontario flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Frontier and Southwest are the most popular carriers operating from Atlanta Hartsfield-Jackson to Ontario

Frontier, Delta and American Airlines are the top three most popular airlines that fly to Ontario from Atlanta according to our data. Frontier is the first choice among our users, with 44% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 7 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.

Historically, on average around 21% of flights between Atlanta and Ontario have experienced a delay on any given week. The average delay length over the past 12 months has been 128 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

Wednesday is statistically the day of the week which experiences the fewest number of delays on this flight route. Monday has historically seen more delays on average compared to the rest of the week.

According to our data, Delta have had the least number of delays on this route over the last 12 months; with about 21% of their flights experiencing any sort of delay.

Denver (DEN) was the most common stop: 86% of momondo users choosing 1-stop flights on this route connected there.

Flights via Denver (DEN) offer the lowest average round-trip price of $249.

Flights connecting via Denver (DEN) have the shortest average one-way travel time: 6h 43m.

Denver (DEN) has the shortest average layover time for this route: 1h 26m.

3 flights are operational daily from Atlanta to Ontario as of October 2026. The most popular departure time for this route is 9:00AM, with 40% of flights per day taking off in the afternoon.

The number of flights available between Atlanta and Ontario is 25 per week as of October 2026. The most frequent departure day is Sun, with 40% of weekly flights leaving on this day.