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C$ 173+ Cheap flights to Boulder

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 30/5. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
10 May — 17 May1
1 adult
1 adult, Economy, 0 bags

Flights to Boulder in 2026

Enter your travel dates to find the best prices.

Cheapest flights to Boulder
Explore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 10 April 2026.

Mon 4/55:50 p.m.
YYZ
-
DEN
2 stops22h 11m
Multiple Airlines
Mon 11/512:15 p.m.
DEN
-
YYZ
1 stop9h 55m
Multiple Airlines
Deal found 6/4C$ 516
Thu 7/59:45 a.m.
YYZ
-
DEN
1 stop16h 24m
Multiple Airlines
Thu 14/56:45 a.m.
DEN
-
YYZ
2 stops13h 20m
Multiple Airlines
Deal found 9/4C$ 523
Mon 4/51:50 p.m.
YTZ
-
DEN
1 stop21h 17m
Multiple Airlines
Mon 11/56:55 a.m.
DEN
-
YTZ
2 stops23h 05m
Multiple Airlines
Deal found 6/4C$ 524
Thu 28/59:50 a.m.
YYZ
-
DEN
2 stops14h 34m
Multiple Airlines
Mon 1/66:10 a.m.
DEN
-
YYZ
1 stop15h 44m
Multiple Airlines
Deal found 6/4C$ 527
Fri 29/59:40 a.m.
YYZ
-
DEN
1 stop16h 58m
Multiple Airlines
Sat 6/62:34 p.m.
DEN
-
YYZ
2 stops14h 21m
Multiple Airlines
Deal found 8/4C$ 528
Fri 5/61:45 p.m.
YYZ
-
DEN
1 stop15h 40m
Multiple Airlines
Wed 17/67:23 a.m.
DEN
-
YYZ
1 stop12h 32m
Multiple Airlines
Deal found 6/4C$ 530
Fri 8/59:40 a.m.
YYZ
-
DEN
1 stop16h 58m
Multiple Airlines
Mon 18/55:05 a.m.
DEN
-
YYZ
2 stops28h 30m
Multiple Airlines
Deal found 6/4C$ 531
Wed 27/59:40 a.m.
YYZ
-
DEN
1 stop12h 26m
Multiple Airlines
Mon 1/610:29 p.m.
DEN
-
YYZ
2 stops29h 16m
Multiple Airlines
Deal found 5/4C$ 533
Wed 13/511:33 a.m.
YYZ
-
DEN
1 stop14h 33m
American Airlines
Wed 20/56:19 a.m.
DEN
-
YYZ
1 stop15h 10m
American Airlines
Deal found 5/4C$ 535
Thu 18/64:45 p.m.
YYZ
-
DEN
1 stop23h 35m
Multiple Airlines
Mon 22/66:10 a.m.
DEN
-
YYZ
1 stop11h 50m
Multiple Airlines
Deal found 8/4C$ 537
Tue 21/49:25 a.m.
YTZ
-
DEN
1 stop8h 39m
Multiple Airlines
Wed 22/42:22 p.m.
DEN
-
YTZ
2 stops19h 18m
Multiple Airlines
Deal found 6/4C$ 538
Mon 4/59:40 a.m.
YYZ
-
DEN
1 stop26h 24m
Multiple Airlines
Wed 13/512:15 p.m.
DEN
-
YYZ
1 stop8h 30m
Multiple Airlines
Deal found 6/4C$ 540

Find flight deals to Boulder

Find the latest flights to Boulder in 2026, with up-to-date prices and availability. In the last 7 days, Cheapflights users made a total of 629,999 searches and data was last updated on 10 April 2026.

Round-trip from

C$ 516

One-way from

C$ 173

Popular in

February

Cheapest in

November

Average price

C$ 621
WestJet
  • WestJet
  • 4/5-11/5
  • 3 total stops
  • 32h 06m total
  • Toronto to Denver
Search Deals
30/5
  • 30/5
  • 1 total stop
  • 13h 47m total
  • Toronto to Boulder
Search Deals
Highest demand for flights based on searches. 6% potential increase in price (C$ 44 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
Search Deals

Cheapflights Fare Finder

 
Locate flights to Boulder that fit your budget, with regularly updated fares and availability. In the last 7 days, Cheapflights users made a total of 629,999 searches and data was last updated on 10 April 2026.
Use the filters below to find and compare flights to Boulder that are best for you.

Fly from

Route

Depart

Return

Price

Cheapest round-trip

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Tue 5/5

6:10 a.m.-9:36 a.m.

1 stop5h 26m

Denver Intl

Wed 6/5

1:25 p.m.-11:59 p.m.

1 stop8h 34m

C$ 596

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Mon 20/4

6:15 a.m.-3:17 p.m.

1 stop11h 02m

Denver Intl

Sun 17/5

12:55 a.m.-8:59 a.m.

1 stop6h 04m

C$ 596

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Fri 17/7

8:40 p.m.-11:20 a.m.

1 stop16h 40m

Denver Intl

Mon 27/7

12:15 p.m.-7:50 p.m.

1 stop29h 35m

C$ 632

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Sat 2/5

12:30 p.m.-7:00 p.m.

1 stop8h 30m

Denver Intl

Tue 5/5

11:25 a.m.-7:52 p.m.

1 stop6h 27m

C$ 632

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 12/6

10:45 a.m.-12:30 p.m.

Nonstop3h 45m

Denver Intl

Mon 15/6

9:05 p.m.-9:54 a.m.

1 stop10h 49m

C$ 632

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Tue 5/5

4:18 p.m.-6:13 p.m.

Nonstop3h 55m

Denver Intl

Tue 12/5

4:45 p.m.-11:59 p.m.

1 stop5h 14m

C$ 635

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 8/5

10:45 a.m.-12:40 p.m.

Nonstop3h 55m

Denver Intl

Mon 11/5

4:45 p.m.-11:59 p.m.

1 stop5h 14m

C$ 636

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Sun 26/4

6:30 a.m.-2:25 p.m.

1 stop9h 55m

Denver Intl

Fri 1/5

12:55 a.m.-10:19 a.m.

1 stop7h 24m

C$ 652

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 5/6

7:43 p.m.-12:30 a.m.

1 stop6h 47m

Denver Intl

Wed 17/6

4:15 p.m.-9:32 p.m.

Nonstop3h 17m

C$ 659

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Wed 5/8

8:40 p.m.-11:20 a.m.

1 stop16h 40m

Denver Intl

Tue 11/8

12:15 p.m.-7:50 p.m.

1 stop29h 35m

C$ 664

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/4

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight to Boulder

Have a flexible travel schedule? Discover the best time to fly to Boulder with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight to Boulder

When is the best time to book a flight to Boulder?

Use this chart to determine the optimal time to book a round-trip flight from Toronto to Boulder. Price data was last updated on 3 April 2026.

Booking 52 days in advance of your planned departure date is, on average, the best time to get cheap flights to Boulder. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

How long is the flight to Boulder?

On average, a flight from Toronto to Boulder takes 10 hours 59 minutes. Flights to Boulder from other popular cities in Canada will vary in length. Below are a few examples of popular routes and their flight times.

Weekly flight availability to Boulder

The most flights from Toronto to Boulder are scheduled on a Monday (10 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (6 on average).

What are the most popular airlines that fly to Boulder?

The most popular airlines flying from Toronto to Boulder are Air Canada, United Airlines and WestJet.

Air Canada
Air Canada
From C$ 88
United Airlines
United Airlines
From C$ 175
WestJet
WestJet
From C$ 167
Delta
Delta
From C$ 141

What are the cheapest airlines that fly to Boulder?

The cheapest airlines flying from Toronto to Boulder are WestJet, United Airlines and Air Canada.

Rainfall in Boulder by month

Plan your trip to Boulder by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Boulder ranges from 13.0 - 58.0 mm per month. May is typically the wettest month, when rainfall can reach 58.0 mm. January is typically the driest time to visit Boulder when rainfall is around 13.0 mm.

Temperature in Boulder by month

Plan your trip to Boulder by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Boulder, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -1.0 C).

Reviews of airlines servicing Boulder

Get insights into the airlines that provide service to Boulder. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Boulder. Reviews last updated 10 April 2026.
Check out reviews from past customers who have flown United Airlines,WestJet, andAir Canada to the United States to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,561 reviews
Check prices

Entertainment

7.1

Boarding

7.7

Food

6.6

Overall

7.4

Crew

8.1

Comfort

7.3

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
United Airlines
7.4
Good
9,561 reviews
United Airlines
7.4
Good
9,561 reviews
Check prices

Entertainment

7.1

Boarding

7.7

Food

6.6

Overall

7.4

Crew

8.1

Comfort

7.3

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
WestJet
7.2
Good
3,320 reviews
United Airlines
7.4
Good
9,561 reviews
Check prices

Entertainment

7.1

Boarding

7.7

Food

6.6

Overall

7.4

Crew

8.1

Comfort

7.3

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats
Air Canada
7.1
Good
10,915 reviews
United Airlines
7.4
Good
9,561 reviews
Check prices

Entertainment

7.1

Boarding

7.7

Food

6.6

Overall

7.4

Crew

8.1

Comfort

7.3

Reviews

1 / 20
6.0
Good

Gerry,Jan 2026

YVR - DEN

Seats were uncomfortable. Second leg of my flight on United had much more comfortable seats

FAQs about flying to Boulder

  • Can I find cheaper flights to Boulder if I am willing to have layovers?

    Yes, flights with layovers are often cheaper than direct flights. Keep an eye out for flight deals to Boulder on Cheapflights that require 1 or 2 stops for potential cost savings.

  • What is the best airline to fly to Boulder?

    Based on reviews from Cheapflights users, Delta is rated the highest out of the airlines that fly to Boulder.

  • How much is a round-trip flight to Boulder?

    A round-trip flight to Boulder will typically cost around C$ 343, however they can be found for as little as C$ 77.

  • Where does the fastest flight to Boulder depart from?

    For those looking to save time traveling to Boulder, Regina offers the quickest one-way flight (2 hours 13 minutes).

  • Does Denver Intl have rental cars?

    Yes. Those touching down at Denver Intl can take advantage of the rental car services offered upon their arrival.

  • Are there hotels close to Denver Intl?

    Yes. Denver Intl has hotels nearby for those requiring accommodations. The Westin Denver International Airport is the closest property to Denver Intl (0.0 km away from Denver Intl).

See more FAQs

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