Search cheap flights from Denver to Ottawa in the next 3 months. Based on Trip.com's latest 7-day data, one-way fares start at US$143, and round-trip tickets start at US$404.

Displayed flight fares from Denver to Ottawa are based on average prices across airlines for the next 3 months, according to the latest Trip.com database.

Denver to Ottawa Flight Details

The distance between Denver and Ottawa is about 2,435.76 km. Based on Trip.com's latest data, travel demand is highest in July. The off-season for travel is October.

Cheapest one-way flight priceUS$143
Cheapest return ticket priceUS$404
Cheapest monthOctober
Peak season for travelJuly
Flight distance2,435.76 km

When is the cheapest time to book flights from Denver to Ottawa?

The cheapest time to fly from Denver to Ottawa: Dec 14 to Dec 21 — one-way prices start at US$142.

Cheapest flights
From price
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  • 714
  • 1421
  • 2128
  • Jan

    284
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  • 1118
  • 1825
  • Feb

    251
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  • 815
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  • Mar

    221
Displayed prices are calculated based on the cheapest average weekly prices of the corresponding route on Trip.com.

Frequently Asked Questions

  • What are the cheapest flights from Denver to Ottawa (DEN-YOW)?

    Based on Trip.com data, Frontier Airlines offers one-way fares as low as US$143 on Cheapest nonstop routes (e.g. DEN to YOW on Mon, Dec 15), while United Airlines offers Cheapest nonstop round-trips from US$404 departing on Tue, Dec 16 and returning on Tue, Dec 23.
  • By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Denver to Ottawa is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.
  • To find best deals on flights from Denver to Ottawa, you can use various tools on Trip.com:
    · Be flexible with your travel dates to get the cheapest flight deal. Now the cheapest flight deal is on Mon, Dec 15, with one-way flights priced at just US$143.
    · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is Frontier Airlines.
    · Set up price alerts to easily monitor ticket prices without having to check every day.
    · Check Trip.com flight deals and promo codes frequently.
    · Avoid peak season unless you book very early. It seems the peak season for Ottawa travel is around July.
    · Get exclusive promo codes for Trip.com app users.
  • The cheapest months to fly from Denver to Ottawa is October, when demand for travel is lower.
  • After crunching the numbers on our December flight calendar, it's currently cheapest to fly from Denver to Ottawa on December 16, 2025 with United Airlines, with prices starting at US$403.
  • The time difference between Ottawa and Denver is 2h.
  • Tickets can only be changed or canceled if permitted by airline policy. To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy. However, if the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.