Cheap Flights from Ontario, CA to Denver, CO from $36

One way Round trip

Adults

Children under 12

Infants under 2 without place

Economy

Business

First

done

Page navigation

Price Calendar Cheap Flights Flights Schedule

On Cheapflightsplus.com you will find 10 direct and 209 connecting flights from Ontario to Denver. You can compare airfare deals from 4 airlines and multiple travel sites from $36, book and save on cheap plane tickets and last minute offers. Also check out ONT-DEN flight schedule to find best flight time, convenient departure and arrival airports.

Find One-Way and Round-Trip Ontario to Denver Flight Deals

To find the cheapest one way airline ticket select the date with the lowest price on the calendar below and click «Find Flights». To search for round-trip flight deals click on the link «Check prices for return flights» and select the date of the return flight. Cheapest flights in November: $36 (one-way), $62 (round-trip).

Direct flights

Check to choose departure date Check to choose departure date

Check prices for return flight

Find flights

Best Flights from Ontario to Denver Today

Take a look at the list of non stop flights and flights with layovers from Ontario to Denver with the lowest price of $36. The fastest direct flight takes 2h 16m and the fastest connecting – 4h 30m.

Price	Departure	Arrival	Flight Duration	Airline	Flight
from $36 Find flight	00:59 Ontario Ontario Int.	04:17 Denver Denver International	2h 18m	Frontier Airlines	F91500
from $48 Find flight	17:21 Ontario Ontario Int.	20:42 Denver Denver International	2h 21m	Frontier Airlines	F92908
from $104 Find flight	13:15 Ontario Ontario Int.	16:31 Denver Denver International	2h 16m	United Airlines	UA1417
from $68 Find flight	17:15 Ontario Ontario Int.	22:45 Denver Denver International	4h 30m layover 1h 12m - Las Vegas	Frontier Airlines	F91358 F94612
from $84 Find flight	06:00 Ontario Ontario Int.	12:06 Denver Denver International	5h 6m layover 1h 45m - Las Vegas	Frontier Airlines	F92232 F92016

Show all tickets

*Departure and arrival times - local. Prices indicated for one-way flights. Information updated on September 15, 2025

Flight Schedule Ontario (California) to Denver (Colorado)

Full flight schedule will help you in detecting at what time planes fly from Ontario to Denver. You can also specify the concrete flights and airlines on the route and how long the flight actually is. Use the calendar for today, tomorrow or other specific date as some flights are available only on certain days of the week.

Departure	Flight Details	Flight Duration	Price
00:59 — 04:17	00:59 — 04:17 F91500 Frontier Airlines Ontario — Denver	2h 18m	Find flight from$36
05:05 — 08:23	05:05 — 08:23 UA1575 United Airlines Ontario — Denver	2h 18m	Find flight from$110
05:10 — 08:27	05:10 — 08:27 UA2446 United Airlines Ontario — Denver	2h 17m	Find flight from$104
05:10 — 08:27	05:10 — 08:27 UA1479 United Airlines Ontario — Denver	2h 17m	Find flight from$105
06:00 — 12:06	17:26 — 18:36 F92232 Frontier Airlines Ontario — Las Vegas 1h 45m stop 08:18 — 11:19 F92016 Frontier Airlines Las Vegas — Denver	5h 6m including layover	Find flight from$84
12:40 — 23:02	12:40 — 18:11 F93132 Frontier Airlines Ontario — Houston 2h 54m stop 21:05 — 23:02 F93227 Frontier Airlines Houston — Denver	9h 22m including layover	Find flight from$84
13:15 — 16:31	13:15 — 16:31 UA1417 United Airlines Ontario — Denver	2h 16m	Find flight from$104
13:15 — 16:32	13:15 — 16:32 UA1697 United Airlines Ontario — Denver	2h 17m	Find flight from$105
13:35 — 16:51	13:35 — 16:51 UA1942 United Airlines Ontario — Denver	2h 16m	Find flight from$154
17:15 — 22:45	13:17 — 14:29 F91358 Frontier Airlines Ontario — Las Vegas 1h 12m stop 20:33 — 23:36 F94612 Frontier Airlines Las Vegas — Denver	4h 30m including layover	Find flight from$68
17:21 — 20:42	17:21 — 20:42 F92908 Frontier Airlines Ontario — Denver	2h 21m	Find flight from$48
17:26 — 04:00 +1 day	09:26 — 10:33 F91358 Frontier Airlines Ontario — Las Vegas 6h 20m stop 06:30 — 09:38 F91994 Frontier Airlines Las Vegas — Denver	9h 34m including layover	Find flight from$68
17:26 — 12:19 +1 day	13:17 — 14:29 F91358 Frontier Airlines Ontario — Las Vegas 14h 35m stop 08:18 — 11:19 F92016 Frontier Airlines Las Vegas — Denver	17h 53m including layover	Find flight from$68
18:28 — 21:47	18:28 — 21:47 UA635 United Airlines Ontario — Denver	2h 19m	Find flight from$134
18:38 — 21:55	18:38 — 21:55 UA368 United Airlines Ontario — Denver	2h 17m	Find flight from$104

Departure	Arrival	Flight Details	Flight Time	Price
		stop stop	including layover	Find flight from$

*Departure and arrival times - local. Updated on September 15, 2025

Flight Information

Below we will explain in detail what the flights cost on the destination from Ontario to Denver depends on and how to choose the most interesting flight option for you.

Distance between Ontario and Denver is 1316 miles. Time difference between the cities is 1h. Airplanes depart 00:59 to 21:41 from 2 Ontario airports and arrive 00:59 to 21:41 to 2 Denver airports. Average flight time is 2h 17m.

The fastest flight 2h 16m
Average flight time 2h 17m
The earliest flight 00:59
The latest flight 21:41
Distance 818 ml

The cheapest months to travel to Denver are november (from 36 $), september (from 36 $), may (from 48 $).

The most expensive months are october (from 93 $), august (from 89 $), july (from 77 $).

What is the lowest airfare Ontario to Denver?

The cheapest plane ticket found by our users is $36. This airfare is for economy class on one-way F91500 flight by Frontier Airlines for September 16, 2025 which leaves Ontario Int. in Ontario at 00:59 am and arrives at Denver Denver International at 04:17.

Economy class

$36

Find

Business class

Find

First class

Find

Popular Airlines on the Route

The flight Ontario — Denver is served by 4 regular airlines and 1 low-cost airline. Most of the flights on this route are operated by Alaska Airlines - 68 departures per week at the price of from $ 119 . And the most expensive tickets are offered by Hawaiian Airlines airline - from $ 659.

Direct flights

There are 10 nonstop flights on the route. The fastest direct flight is UA1417 by United Airlines takes 2h 16m and the cheapest is F91500 by Frontier Airlines for $36.

F9 - Frontier Airlines

from $36

Find
UA - United Airlines

from $104

Find

See more direct flights

Connecting Flights

There are 209 flights with layovers on the route. The fastest connecting flight is F91358 by Frontier Airlines takes 4h 30m and the cheapest is F91500 by Frontier Airlines for $68.

AS - Alaska Airlines

from $119

Find
F9 - Frontier Airlines

from $68

Find
HA - Hawaiian Airlines

from $111

Find
UA - United Airlines

from $173

Find

See more connecting flights

Airports

You can fly from Ontario to Denver from 2 airports (Ontario Int., International Heliport).

Ontario airports

Ontario Int.-ONT

from $36
Find
International Heliport-JIO

Find

Denver airports

Denver International-DEN

Find
Arapahoe Co-APA

Find

Airplanes

There are flights to Denver from Ontario by 4 airlines that use 0 aircraft brands. They range from huge modern airplanes to small-sized.

Top Domestic Destinations from Ontario

You may also consider searching for discounted plane tickets to some other popular places from Ontario within United States.

Ontario — Phoenix

from $56

Find
Ontario — Denver

from $65

Find
Ontario — Austin

from $67

Find
Ontario — Miami

from $62

Find
Ontario — Tucson

from $80

Find
Ontario — Las Vegas

from $63

Find
Ontario — Seattle

from $65

Find
Ontario — Boise

from $70

Find
Ontario — Chicago

from $78

Find
Ontario — Philadelphia

from $62

Find

Top International Destinations from Ontario

Our state-of-the art metasearch will definitely provide you with the best airfare on international flights. We’re proud to partner with many reliable travel suppliers located outside the US what gives us an opportunity to offer the most competitive prices on far destinations.

Ontario — London

from $62

Find
Ontario — San Jose

from $61

Find
Ontario — Guadalajara

from $70

Find
Ontario — Cancun

from $74

Find

How to book a plane ticket yourself?

Fill in the search parameters — cities of departure and destination, departure and return dates and click «Find flights»
Select the best flight that you like. Please, check the airports of departure and arrival. Select the best fare, but pay attention to the following flight details - airports of departure and arrival, flight duration and layovers. Please use filters and sort to find the best flight.
Click «Buy» when you are ready — our system will redirect you to the site that sells the selected flight ticket.
Fill in all passenger and payment information — passport and contact information, please double check all passengers’ names and make a payment for your itinerary.
That's it — you will receive an email with your e-ticket usually within 10 minutes after your flight is confirmed. Please, print the e-ticket and have it with you at the airport. You would need to have only a passport and/or a required form of ID to travel. Please, check your Visa requirements if you travel outside of the United States or Canada.
To find a plane ticket, please select dates.