Denver (DEN) to Ontario (ONT) flights
Southwest Airlines, Frontier Airlines, United Airlines fly nonstop from Denver International Airport to Ontario International Airport, with about 55 flights a week in July 2026. The 819-mile flight takes about 2h 16m gate to gate.
- Distance
- 819 mi · 1,318 km
- Flight time
- 2h 16m
- Airlines
- 3
- Seats filled
- 80%
Airlines flying DEN to ONT
| Airline | Flights a week | Aircraft | Passengers (12 months) | Flight time |
|---|---|---|---|---|
| Southwest Airlines | 27 | Boeing 737 MAX 8, Boeing 737-800, Boeing 737-700 / MAX 7 | 168,250 | 2h 15m |
| Frontier Airlines | 14 | Airbus A320neo, Airbus A321, Airbus A320-100/200 | 88,168 | 2h 18m |
| United Airlines | 14 | Boeing 737-800, Airbus A320-100/200, Boeing 737 MAX 9 | 116,920 | 2h 17m |
Airlines are the operating carrier: regional airlines such as SkyWest or Horizon often fly under a larger airline's brand.
DEN to ONT flight schedule
12 flight numbers flew this route in August 2026, 5 of them almost daily. The first usually leaves at 8:45am and the last at 10:29pm. Times are local and can change; check with the airline before you book.
| Flight | Departs | Arrives | Days flown in August 2026 | On time (12 months) |
|---|---|---|---|---|
| F9 2907Frontier Airlines | 8:45am | 10:04am | 31 | 92% |
| WN 4794Southwest Airlines | 9:00am | 10:15am | 12 | 92% |
| WN 1596Southwest Airlines | 9:05am | 10:20am | 25 | 88% |
| UA 430United Airlines | 11:30am | 12:50pm | 31 | 88% |
| WN 2050Southwest Airlines | 12:45pm | 2:00pm | 12 | 83% |
| WN 3959Southwest Airlines | 3:05pm | 4:25pm | 4 | n/a |
| WN 4773Southwest Airlines | 5:50pm | 7:20pm | 12 | 33% |
| WN 3775Southwest Airlines | 6:05pm | 7:35pm | 4 | n/a |
| UA 2028United Airlines | 7:30pm | 8:53pm | 31 | 69% |
| WN 4341Southwest Airlines | 7:30pm | 8:50pm | 4 | n/a |
| WN 1598Southwest Airlines | 8:50pm | 10:10pm | 18 | 29% |
| F9 1261Frontier Airlines | 10:29pm | 11:50pm | 31 | 77% |
Is DEN to ONT on time?
From September 2025 to August 2026, 75% of 2,623 flights arrived within 15 minutes of schedule and 0.2% were cancelled. Flights leaving around 8am were the most punctual (92%), those around 9pm the least (55%). Most delay time was caused by late-arriving aircraft (55%).
| Airline | Flights | On time | Average delay | Cancelled |
|---|---|---|---|---|
| Southwest Airlines | 1,269 | 70% | 17 min | 0.2% |
| United Airlines | 797 | 79% | 15 min | 0% |
| Frontier Airlines | 557 | 80% | 13 min | 0.5% |
Airlines as sold: flights operated by regional partners count under the airline on the ticket. Average delay is across all completed flights, early arrivals counted as zero.
On-time arrivals by departure time
| Scheduled departure | Flights | On time, relative | On time |
|---|---|---|---|
| 7am to 8am | 104 | 83% | |
| 8am to 9am | 360 | 92% | |
| 11am to 12pm | 417 | 86% | |
| 1pm to 2pm | 162 | 80% | |
| 4pm to 5pm | 96 | 73% | |
| 5pm to 6pm | 56 | 46% | |
| 6pm to 7pm | 168 | 57% | |
| 7pm to 8pm | 394 | 71% | |
| 8pm to 9pm | 170 | 61% | |
| 9pm to 10pm | 137 | 55% | |
| 10pm to 11pm | 344 | 67% |
Flights by month
| Month | Flights | Flights, relative | Passengers |
|---|---|---|---|
| August 2025 | 255 | 36,143 | |
| September 2025 | 237 | 32,747 | |
| October 2025 | 242 | 35,574 | |
| November 2025 | 220 | 31,532 | |
| December 2025 | 197 | 28,203 | |
| January 2026 | 186 | 25,493 | |
| February 2026 | 172 | 23,466 | |
| March 2026 | 200 | 27,732 | |
| April 2026 | 205 | 29,240 | |
| May 2026 | 243 | 33,844 | |
| June 2026 | 250 | 35,003 | |
| July 2026 | 243 | 34,361 |
Related
Source: US Department of Transportation, T-100 Segment data, August 2025 to July 2026.