Find us faster — just Google flightlist (one word)

Flights from Denver to Ontario (DEN to ONT)

Discover alternate routes & cheap one way flights from Denver to Ontario (DEN to ONT) within a departure date range.

⭐ Search by country or region to discover cheaper routes you didn't know existed. Example: Netherlands → Italy or Europe → South-East Asia.

Budget
Travel Time
Layover Time
Loading…
  • USD 157
    Frontier Airlines
    10:25am - 11:54am
    Sat Dec 31st
    2h 29m
    Denver (DEN) → Ontario (ONT)
    Direct

    Sat Dec 31st 2022 Frontier Airlines · F9 977 Depart at 10:25 am from Denver (DEN) Fly for 2h 29m Arrive at 11:54 am in Ontario (ONT)

  • USD 167
    Spirit AirlinesFrontier Airlines
    12:45pm - 7:49pm
    Sat Dec 31st
    8h 4m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Spirit Airlines · NK 1244 Depart at 12:45 pm from Denver (DEN) Fly for 2h 0m Arrive at 1:45 pm in Las Vegas (LAS)

    Layover in Las Vegas for 4h 58m

    Sat Dec 31st 2022 Frontier Airlines · F9 2187 Depart at 6:43 pm from Las Vegas (LAS) Fly for 1h 6m Arrive at 7:49 pm in Ontario (ONT)

  • USD 169
    Frontier Airlines
    10:56pm - 12:25am
    Fri Dec 30th
    2h 29m
    Denver (DEN) → Ontario (ONT)
    Direct

    Fri Dec 30th 2022 Frontier Airlines · F9 975 Depart at 10:56 pm from Denver (DEN) Fly for 2h 29m Arrive at 12:25 am in Ontario (ONT)

  • USD 169
    Frontier Airlines
    10:25am - 11:54am
    Fri Dec 30th
    2h 29m
    Denver (DEN) → Ontario (ONT)
    Direct

    Fri Dec 30th 2022 Frontier Airlines · F9 977 Depart at 10:25 am from Denver (DEN) Fly for 2h 29m Arrive at 11:54 am in Ontario (ONT)

  • USD 179
    Frontier Airlines
    10:25am - 11:54am
    Sat Dec 31st
    2h 29m
    Denver (DEN) → Ontario (ONT)
    Direct

    Sat Dec 31st 2022 Frontier Airlines · F9 977 Depart at 10:25 am from Denver (DEN) Fly for 2h 29m Arrive at 11:54 am in Ontario (ONT)

  • USD 185
    Frontier Airlines
    9:26pm - 4:08pm
    Fri Dec 30th
    19h 42m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Frontier Airlines · F9 71 Depart at 9:26 pm from Denver (DEN) Fly for 2h 9m Arrive at 10:35 pm in Las Vegas (LAS)

    Layover in Las Vegas for 16h 24m

    Sat Dec 31st 2022 Frontier Airlines · F9 2189 Depart at 2:59 pm from Las Vegas (LAS) Fly for 1h 9m Arrive at 4:08 pm in Ontario (ONT)

  • USD 185
    Frontier Airlines
    7:56pm - 4:08pm
    Fri Dec 30th
    21h 12m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Frontier Airlines · F9 777 Depart at 7:56 pm from Denver (DEN) Fly for 2h 4m Arrive at 9:00 pm in Las Vegas (LAS)

    Layover in Las Vegas for 17h 59m

    Sat Dec 31st 2022 Frontier Airlines · F9 2189 Depart at 2:59 pm from Las Vegas (LAS) Fly for 1h 9m Arrive at 4:08 pm in Ontario (ONT)

  • USD 282
    Frontier Airlines
    8:58am - 4:08pm
    Sat Dec 31st
    8h 10m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Frontier Airlines · F9 773 Depart at 8:58 am from Denver (DEN) Fly for 2h 5m Arrive at 10:03 am in Las Vegas (LAS)

    Layover in Las Vegas for 4h 56m

    Sat Dec 31st 2022 Frontier Airlines · F9 2189 Depart at 2:59 pm from Las Vegas (LAS) Fly for 1h 9m Arrive at 4:08 pm in Ontario (ONT)

  • USD 282
    Frontier Airlines
    6:25am - 4:08pm
    Sat Dec 31st
    10h 43m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Frontier Airlines · F9 771 Depart at 6:25 am from Denver (DEN) Fly for 2h 8m Arrive at 7:33 am in Las Vegas (LAS)

    Layover in Las Vegas for 7h 26m

    Sat Dec 31st 2022 Frontier Airlines · F9 2189 Depart at 2:59 pm from Las Vegas (LAS) Fly for 1h 9m Arrive at 4:08 pm in Ontario (ONT)

  • USD 282
    Frontier Airlines
    8:58am - 7:49pm
    Sat Dec 31st
    11h 51m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Frontier Airlines · F9 773 Depart at 8:58 am from Denver (DEN) Fly for 2h 5m Arrive at 10:03 am in Las Vegas (LAS)

    Layover in Las Vegas for 8h 40m

    Sat Dec 31st 2022 Frontier Airlines · F9 2187 Depart at 6:43 pm from Las Vegas (LAS) Fly for 1h 6m Arrive at 7:49 pm in Ontario (ONT)

  • USD 282
    Frontier Airlines
    6:25am - 7:49pm
    Sat Dec 31st
    14h 24m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Frontier Airlines · F9 771 Depart at 6:25 am from Denver (DEN) Fly for 2h 8m Arrive at 7:33 am in Las Vegas (LAS)

    Layover in Las Vegas for 11h 10m

    Sat Dec 31st 2022 Frontier Airlines · F9 2187 Depart at 6:43 pm from Las Vegas (LAS) Fly for 1h 6m Arrive at 7:49 pm in Ontario (ONT)

  • USD 286
    Frontier Airlines
    4:45pm - 9:40pm
    Fri Dec 30th
    5h 55m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Frontier Airlines · F9 775 Depart at 4:45 pm from Denver (DEN) Fly for 2h 3m Arrive at 5:48 pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 48m

    Fri Dec 30th 2022 Frontier Airlines · F9 2187 Depart at 8:36 pm from Las Vegas (LAS) Fly for 1h 4m Arrive at 9:40 pm in Ontario (ONT)

  • USD 325
    Frontier AirlinesUnited Airlines
    11:29am - 4:08pm
    Sat Dec 31st
    5h 39m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 United Airlines · UA 373 Depart at 11:29 am from Denver (DEN) Fly for 2h 2m Arrive at 12:31 pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 28m

    Sat Dec 31st 2022 Frontier Airlines · F9 2189 Depart at 2:59 pm from Las Vegas (LAS) Fly for 1h 9m Arrive at 4:08 pm in Ontario (ONT)

  • USD 325
    Frontier AirlinesUnited Airlines
    1:26pm - 7:49pm
    Sat Dec 31st
    7h 23m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 United Airlines · UA 1252 Depart at 1:26 pm from Denver (DEN) Fly for 1h 59m Arrive at 2:25 pm in Las Vegas (LAS)

    Layover in Las Vegas for 4h 18m

    Sat Dec 31st 2022 Frontier Airlines · F9 2187 Depart at 6:43 pm from Las Vegas (LAS) Fly for 1h 6m Arrive at 7:49 pm in Ontario (ONT)

  • USD 326
    Alaska Airlines
    5:30pm - 11:57pm
    Fri Dec 30th
    7h 27m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Alaska Airlines · AS 556 Depart at 5:30 pm from Denver (DEN) Fly for 3h 7m Arrive at 7:37 pm in Seattle (SEA)

    Layover in Seattle for 1h 48m

    Fri Dec 30th 2022 Alaska Airlines · AS 775 Depart at 9:25 pm from Seattle (SEA) Fly for 2h 32m Arrive at 11:57 pm in Ontario (ONT)

  • USD 327
    Spirit AirlinesFrontier Airlines
    12:45pm - 5:02pm
    Fri Dec 30th
    5h 17m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Spirit Airlines · NK 1244 Depart at 12:45 pm from Denver (DEN) Fly for 2h 0m Arrive at 1:45 pm in Las Vegas (LAS)

    Layover in Las Vegas for 2h 10m

    Fri Dec 30th 2022 Frontier Airlines · F9 2189 Depart at 3:55 pm from Las Vegas (LAS) Fly for 1h 7m Arrive at 5:02 pm in Ontario (ONT)

  • USD 328
    United Airlines
    7:17pm - 8:36pm
    Thu Dec 29th
    2h 19m
    Denver (DEN) → Ontario (ONT)
    Direct

    Thu Dec 29th 2022 United Airlines · UA 336 Depart at 7:17 pm from Denver (DEN) Fly for 2h 19m Arrive at 8:36 pm in Ontario (ONT)

  • USD 328
    United Airlines
    7:17pm - 8:36pm
    Sat Dec 31st
    2h 19m
    Denver (DEN) → Ontario (ONT)
    Direct

    Sat Dec 31st 2022 United Airlines · UA 336 Depart at 7:17 pm from Denver (DEN) Fly for 2h 19m Arrive at 8:36 pm in Ontario (ONT)

  • USD 328
    United Airlines
    11:15am - 12:39pm
    Fri Dec 30th
    2h 24m
    Denver (DEN) → Ontario (ONT)
    Direct

    Fri Dec 30th 2022 United Airlines · UA 430 Depart at 11:15 am from Denver (DEN) Fly for 2h 24m Arrive at 12:39 pm in Ontario (ONT)

  • USD 333
    Alaska Airlines
    2:55pm - 11:57pm
    Fri Dec 30th
    10h 2m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Alaska Airlines · AS 620 Depart at 2:55 pm from Denver (DEN) Fly for 3h 5m Arrive at 5:00 pm in Seattle (SEA)

    Layover in Seattle for 4h 25m

    Fri Dec 30th 2022 Alaska Airlines · AS 775 Depart at 9:25 pm from Seattle (SEA) Fly for 2h 32m Arrive at 11:57 pm in Ontario (ONT)

  • USD 333
    Alaska Airlines
    7:00am - 6:07pm
    Fri Dec 30th
    12h 7m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Alaska Airlines · AS 643 Depart at 7:00 am from Denver (DEN) Fly for 3h 10m Arrive at 9:10 am in Seattle (SEA)

    Layover in Seattle for 6h 25m

    Fri Dec 30th 2022 Alaska Airlines · AS 420 Depart at 3:35 pm from Seattle (SEA) Fly for 2h 32m Arrive at 6:07 pm in Ontario (ONT)

  • USD 337
    Delta Air Lines
    12:43pm - 4:05pm
    Fri Dec 30th
    4h 22m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Delta Air Lines · DL 2835 Depart at 12:43 pm from Denver (DEN) Fly for 1h 26m Arrive at 2:09 pm in Salt Lake City (SLC)

    Layover in Salt Lake City for 1h 8m

    Fri Dec 30th 2022 Delta Air Lines · DL 2354 Depart at 3:17 pm from Salt Lake City (SLC) Fly for 1h 48m Arrive at 4:05 pm in Ontario (ONT)

  • USD 337
    Delta Air Lines
    8:38am - 12:33pm
    Fri Dec 30th
    4h 55m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 Delta Air Lines · DL 2165 Depart at 8:38 am from Denver (DEN) Fly for 1h 46m Arrive at 10:24 am in Salt Lake City (SLC)

    Layover in Salt Lake City for 1h 11m

    Fri Dec 30th 2022 Delta Air Lines · DL 3618 Depart at 11:35 am from Salt Lake City (SLC) Fly for 1h 58m Arrive at 12:33 pm in Ontario (ONT)

  • USD 337
    Delta Air Lines
    5:59pm - 10:11pm
    Sat Dec 31st
    5h 12m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Delta Air Lines · DL 2383 Depart at 5:59 pm from Denver (DEN) Fly for 1h 34m Arrive at 7:33 pm in Salt Lake City (SLC)

    Layover in Salt Lake City for 1h 42m

    Sat Dec 31st 2022 Delta Air Lines · DL 2425 Depart at 9:15 pm from Salt Lake City (SLC) Fly for 1h 56m Arrive at 10:11 pm in Ontario (ONT)

  • USD 338
    Alaska Airlines
    11:45am - 6:07pm
    Sat Dec 31st
    7h 22m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Alaska Airlines · AS 682 Depart at 11:45 am from Denver (DEN) Fly for 3h 5m Arrive at 1:50 pm in Seattle (SEA)

    Layover in Seattle for 1h 45m

    Sat Dec 31st 2022 Alaska Airlines · AS 420 Depart at 3:35 pm from Seattle (SEA) Fly for 2h 32m Arrive at 6:07 pm in Ontario (ONT)

  • USD 345
    American Airlines
    6:42pm - 9:33pm
    Fri Dec 30th
    3h 51m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Fri Dec 30th 2022 American Airlines · AA 1926 Depart at 6:42 pm from Denver (DEN) Fly for 1h 58m Arrive at 8:40 pm in Phoenix (PHX)

    Layover in Phoenix for 0h 34m

    Fri Dec 30th 2022 American Airlines · AA 634 Depart at 9:14 pm from Phoenix (PHX) Fly for 1h 19m Arrive at 9:33 pm in Ontario (ONT)

  • USD 345
    American Airlines
    11:55am - 3:16pm
    Sat Dec 31st
    4h 21m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 American Airlines · AA 1991 Depart at 11:55 am from Denver (DEN) Fly for 2h 8m Arrive at 2:03 pm in Phoenix (PHX)

    Layover in Phoenix for 0h 56m

    Sat Dec 31st 2022 American Airlines · AA 1697 Depart at 2:59 pm from Phoenix (PHX) Fly for 1h 17m Arrive at 3:16 pm in Ontario (ONT)

  • USD 345
    American Airlines
    7:04am - 11:07am
    Wed Dec 28th
    5h 3m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Wed Dec 28th 2022 American Airlines · AA 1404 Depart at 7:04 am from Denver (DEN) Fly for 1h 57m Arrive at 9:01 am in Phoenix (PHX)

    Layover in Phoenix for 1h 46m

    Wed Dec 28th 2022 American Airlines · AA 5835 Depart at 10:47 am from Phoenix (PHX) Fly for 1h 20m Arrive at 11:07 am in Ontario (ONT)

  • USD 371
    United Airlines
    11:15am - 12:39pm
    Sat Dec 31st
    2h 24m
    Denver (DEN) → Ontario (ONT)
    Direct

    Sat Dec 31st 2022 United Airlines · UA 430 Depart at 11:15 am from Denver (DEN) Fly for 2h 24m Arrive at 12:39 pm in Ontario (ONT)

  • USD 381
    United Airlines
    7:24pm - 12:15am
    Sat Dec 31st
    5h 51m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 United Airlines · UA 519 Depart at 7:24 pm from Denver (DEN) Fly for 2h 50m Arrive at 9:14 pm in San Francisco (SFO)

    Layover in San Francisco for 1h 32m

    Sat Dec 31st 2022 United Airlines · UA 5284 Depart at 10:46 pm from San Francisco (SFO) Fly for 1h 29m Arrive at 12:15 am in Ontario (ONT)

  • USD 385
    Frontier AirlinesUnited Airlines
    12:07pm - 5:53pm
    Sat Dec 31st
    6h 46m
    Denver (DEN) → Ontario (ONT)
    1 Stop

    Sat Dec 31st 2022 Frontier Airlines · F9 665 Depart at 12:07 pm from Denver (DEN) Fly for 2h 56m Arrive at 2:03 pm in San Francisco (SFO)

    Layover in San Francisco for 2h 29m

    Sat Dec 31st 2022 United Airlines · UA 5672 Depart at 4:32 pm from San Francisco (SFO) Fly for 1h 21m Arrive at 5:53 pm in Ontario (ONT)

  • USD 451
    United Airlines
    11:15am - 12:39pm
    Thu Dec 29th
    2h 24m
    Denver (DEN) → Ontario (ONT)
    Direct

    Thu Dec 29th 2022 United Airlines · UA 430 Depart at 11:15 am from Denver (DEN) Fly for 2h 24m Arrive at 12:39 pm in Ontario (ONT)

@sarahbb1
Sarah Belizaire
@sarahbb1

Have flexible travel plans or looking for alternative routes given the chaos? Check out all the connection possibilities via a super helpful site created by @ismaelyws flightlist.io thanks to @andy_travels for the recommendation #travel #flights

@eyupitsjohn
John Ford
@eyupitsjohn

There seem to be lots of sites launching at the moment that promise to find you cheap one way flights but not many have the professional finish of Flightlist by @ismaelyws #travel #flights

@andy_travels
Andy Travels
@andy_travels

@ismaelyws Just tried out Flightlist for the first time. Really nice idea, well made, and just what I need at the moment 👍

@travelwitbender
Travel With Bender
@travelwitbender

Did you spot my recent article about how to score cheap one way flights? ✈️ FlightList is my new secret tool for discovering cheap routes, within a departure date range. Plus you can also search by country/region for departures & destinations. Powerful! 💪

Explore Flight Options

Cheap Flight Search Tips

Tips to help you find the cheapest flights from Denver to Ontario (DEN to ONT).

  • Book 45-90 days before your departure date.
  • Fly during weekdays (Monday-Thursday).
  • Airfare Sales: Airlines sometimes offer huge discounts and since we take a bottom-up approach these flights will appear first in the results, so check back regularly because they don't usually last long.

Why I Built FlightList

❝As someone who works remotely & travels frequently, I always book one way flights and I'm flexible on my departure dates. I look for the best deals. Most sites require you to enter a specific departure date and clutter the page with uneccessary options, images and ads. I want something simple and minimal which allows me to search by departure date range & display a list of flights with the ability to filter according to my needs. So, I built FlightList to solve my own problem & help other travelers who may have the same frustration. It's how I imagine a flight booking site should be.❞

- Hans Desjarlais, Founder & Creator Hans Desjarlais