The observed direct connection between Denver International Airport (DEN) and Ontario International Airport (ONT) covers approximately 818 mi. The estimated flight time is around 2h 10m. Air Transport International, FedEx, Frontier Airlines, Southwest Airlines, United Airlines, UPS Airlines and Volaris have been observed on this connection in the available route data.
Frequently asked questions about this route
How far is Denver from Ontario by air?
The great-circle distance between Denver International Airport and Ontario International Airport is approximately 818 mi.
How long is the flight from Denver to Ontario?
Based on the distance, the estimated flight time is about 2h 10m. This is an estimate, not a schedule.
Is there a direct connection from Denver to Ontario?
Yes, a direct connection between DEN and ONT has been observed in our route data.
Which airlines have been observed on this route?
In the available route data: Air Transport International, FedEx, Frontier Airlines, Southwest Airlines, United Airlines, UPS Airlines and Volaris.
How often is there a flight from Denver to Ontario?
On average around 9 flights a day, measured over twelve months (October 2025 to September 2026) in the flight archive, with 3,123 observed flights. Mainly Southwest Airlines, United Airlines, UPS Airlines. That is an observation, not a timetable.
What is the current time difference between Denver and Ontario?
Ontario is currently 1 hour behind Denver.
Where this data comes from
The route data comes from the flight archive (ADS-B, adsb.lol): which connections actually flew over the last twelve full months and who flew them, combined with our own airport, runway, and airline datasets. It is reference data about observed routes - not a current timetable and no claim about bookability.
The frequency and aircraft on this page come from the flight archive (ADS-B, 12 months, October 2025 to September 2026), summarized per route per month. We do not see every flight, so it is a floor, not a count.