Ontario to Denver (ONT-DEN): nonstop flights and who flies them

United Airlines and Frontier Airlines fly nonstop between Ontario (ONT) and Denver (DEN), roughly 28 times a week. The timetable below shows the nonstop scheduled at 2h 21m to 2h 26m for the 817 miles.

Schedule last confirmed . Departure times come from 2LNR's schedule data; confirm with the airline before you book.

Updated .

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28
Flights a week, 4-week average
2h 21m to 2h 26m
Scheduled flight time
817 mi
Nonstop distance
Free
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Ontario to Denver flight schedule

Scheduled nonstop departures for ONT to DEN starting October 22, 2026, last checked against our schedule feed on October 18, 2026. Airlines retime and cancel flights, so confirm with the airline before you book.

Schedule data dated .

Scheduled nonstop departures from Ontario (ONT) to Denver (DEN)
Date Flight Airline Departs ONT Arrives DEN Duration Aircraft
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:1509:412h 26mAirbus A320neo
F9 2908Frontier Airlines11:5215:182h 26mAirbus A321
UA 1263United Airlines13:2416:452h 21mBoeing 737 MAX 9
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:1509:412h 26mAirbus A320neo
F9 2908Frontier Airlines11:5215:182h 26mAirbus A320neo
UA 1263United Airlines13:2416:452h 21mBoeing 737 MAX 9
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:1509:412h 26mAirbus A320neo
F9 1262Frontier Airlines11:5215:182h 26mAirbus A321
UA 1263United Airlines13:2216:452h 23mAirbus A319
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:1509:412h 26mAirbus A320neo
F9 2908Frontier Airlines11:5215:182h 26mAirbus A321neo family
UA 1263United Airlines13:2416:452h 21mBoeing 737 MAX 9
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:1509:412h 26mAirbus A320neo
F9 2908Frontier Airlines11:5215:182h 26mAirbus A320neo
UA 1263United Airlines13:2416:452h 21mBoeing 737 MAX 9
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:2509:462h 21mAirbus A320neo
UA 1263United Airlines13:2216:452h 23mAirbus A319
F9 1262Frontier Airlines14:3517:572h 22mAirbus A320neo
UA 2446United Airlines05:0008:212h 21mBoeing 737-900
F9 1500Frontier Airlines06:2509:462h 21mAirbus A320neo
UA 1263United Airlines13:2416:452h 21mBoeing 737 MAX 9
F9 1262Frontier Airlines14:3517:572h 22mAirbus A320neo

Showing all 28 scheduled ONT to DEN departures across 7 days with service, starting October 22, 2026. Later dates are on the interactive map.

Departure and arrival times are local at their own airport, so an arrival can fall on a different local date than the departure; the duration column is the true elapsed flying time. A dash means the airline hasn't filed that value in the schedule data we hold. Aircraft are the equipment the airline filed, named where the code pins down one type and shown as the family or the bare code where it doesn't. Swaps can happen up to departure.

See every ONT to DEN date on the interactive map

Aircraft on the Ontario to Denver nonstop

In the schedule table on this page, United Airlines flies the Boeing 737-900, the Boeing 737 MAX 9, and the Airbus A319, and Frontier Airlines flies the Airbus A320neo, the Airbus A321, and the Airbus A321neo family. Each linked aircraft page shows where that airline schedules it. Airlines can swap aircraft up to departure.

The full ONT to DEN nonstop schedule

This page carries the full ONT to DEN nonstop schedule, who operates each departure and how often it runs; the reverse direction is linked below.

See the schedule

Who operates each ONT to DEN nonstop and how often it runs, from 2LNR's schedule data.

Plan on the map

See ONT to DEN on the interactive route map, with schedules, connections, and route statistics.

Airlines flying Ontario to Denver nonstop

Carriers operating ONT to DEN nonstop in the current schedule.

See ONT to DEN on the interactive map →

Frequently asked questions about ONT to DEN

How long is the flight from Ontario (ONT) to Denver (DEN)?
Scheduled flight times from Ontario (ONT) to Denver (DEN) run from 2h 21m to 2h 26m across the departures in the schedule table on this page. The nonstop covers about 817 miles, and airlines adjust scheduled times by season, so confirm with the airline before you book.
Which airlines fly nonstop from ONT to DEN?
United Airlines and Frontier Airlines fly ONT to DEN nonstop. 2LNR doesn't show award or upgrade space for any of them on ONT to DEN, so this page carries the schedule rather than a space claim.
How many flights a week are there from ONT to DEN?
About 28 nonstop flights a week run between Ontario (ONT) and Denver (DEN) in the current schedule, operated by United Airlines and Frontier Airlines. Frequency shifts by season, and the schedule table on this page shows what is scheduled next.
What time do flights from ONT to DEN depart?
Scheduled ONT to DEN nonstops in the next 7 days with service leave between 05:00 and 14:35, local time at Ontario. The schedule table on this page lists every departure by date, with its arrival time and aircraft.
Which flights operate ONT to DEN nonstop?
In the schedule table on this page, ONT to DEN nonstops fly as F9 1262, F9 1500, and F9 2908 on Frontier Airlines, and UA 1263 and UA 2446 on United Airlines. The table lists each departure by date with its times and aircraft.
Does 2LNR show upgrade or award space on ONT to DEN?
Not on this route: 2LNR doesn't show award or upgrade space for any airline flying ONT to DEN. The page carries the full ONT to DEN nonstop schedule and who flies each departure, and the reverse direction is linked below.

See the full ONT to DEN nonstop schedule

Every scheduled departure on this route, with who flies it. 2LNR shows upgrade and award space by date on the carriers it tracks, the next 14 days free on every product and the full horizon on Pro.

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