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C$ 216+ 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 21/9. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
12 Jul — 19 Jul1
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 12 June 2026.

Wed 5/88:00 a.m.
YYZ
-
DEN
1 stop29h 20m
WestJet
Tue 11/812:15 p.m.
DEN
-
YYZ
1 stop9h 55m
WestJet
Deal found 8/6C$ 469
Wed 9/98:40 p.m.
YTZ
-
DEN
1 stop18h 20m
Multiple Airlines
Tue 15/95:56 p.m.
DEN
-
YTZ
1 stop18h 29m
Multiple Airlines
Deal found 8/6C$ 482
Thu 20/82:50 p.m.
YYZ
-
DEN
1 stop22h 30m
WestJet
Thu 27/812:15 p.m.
DEN
-
YYZ
1 stop9h 55m
WestJet
Deal found 8/6C$ 485
Tue 28/712:55 p.m.
YYZ
-
DEN
1 stop10h 46m
Multiple Airlines
Fri 31/710:15 a.m.
DEN
-
YYZ
1 stop8h 35m
Multiple Airlines
Deal found 11/6C$ 497
Mon 24/88:35 p.m.
YYZ
-
DEN
1 stop9h 23m
Multiple Airlines
Tue 25/87:26 p.m.
DEN
-
YYZ
1 stop9h 13m
Multiple Airlines
Deal found 10/6C$ 504
Wed 1/75:20 p.m.
YYZ
-
DEN
2 stops20h 00m
WestJet
Mon 6/712:15 p.m.
DEN
-
YYZ
1 stop8h 30m
WestJet
Deal found 10/6C$ 510
Fri 17/72:25 p.m.
YYZ
-
DEN
2 stops22h 55m
WestJet
Tue 21/712:15 p.m.
DEN
-
YYZ
1 stop8h 30m
WestJet
Deal found 11/6C$ 515
Tue 21/72:25 p.m.
YYZ
-
DEN
2 stops22h 55m
WestJet
Sun 2/812:15 p.m.
DEN
-
YYZ
2 stops25h 05m
WestJet
Deal found 10/6C$ 517
Tue 14/75:20 p.m.
YYZ
-
DEN
2 stops20h 00m
WestJet
Tue 21/712:15 p.m.
DEN
-
YYZ
1 stop9h 55m
WestJet
Deal found 11/6C$ 518
Thu 16/72:50 p.m.
YYZ
-
DEN
1 stop22h 30m
WestJet
Mon 20/712:15 p.m.
DEN
-
YYZ
1 stop9h 55m
WestJet
Deal found 8/6C$ 520
Mon 24/88:40 p.m.
YKF
-
DEN
1 stop16h 40m
WestJet
Mon 31/812:15 p.m.
DEN
-
YKF
1 stop29h 35m
WestJet
Deal found 11/6C$ 524
Thu 27/89:00 a.m.
YYZ
-
DEN
1 stop28h 20m
WestJet
Sun 30/812:15 p.m.
DEN
-
YYZ
1 stop9h 55m
WestJet
Deal found 7/6C$ 524

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 12 June 2026.

Round-trip from

C$ 469

One-way from

C$ 216

Popular in

February

Cheapest in

November

Average price

C$ 697
WestJet
  • WestJet
  • 5/8-11/8
  • 2 total stops
  • 39h 15m total
  • Toronto to Denver
Search Deals
21/9
  • 21/9
  • 1 total stop
  • 29h 49m total
  • Toronto to Boulder
Search Deals
Highest demand for flights based on searches. 3% potential increase in price (C$ 25 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 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 12 June 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

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Mon 24/8

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

1 stop16h 40m

Denver Intl

Mon 31/8

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

1 stop29h 35m

C$ 524

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Tue 14/7

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

1 stop16h 40m

Denver Intl

Sat 18/7

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

1 stop29h 35m

C$ 532

HamiltonDenver

YHM - DEN

YHMDEN

Hamilton

Mon 24/8

6:10 p.m.-11:20 a.m.

1 stop19h 10m

Denver Intl

Mon 31/8

12:15 p.m.-5:15 p.m.

1 stop27h 00m

C$ 549

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Thu 17/9

1:40 p.m.-12:29 a.m.

1 stop12h 49m

Denver Intl

Mon 21/9

6:25 a.m.-6:00 p.m.

1 stop9h 35m

C$ 552

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Mon 12/10

3:59 p.m.-9:40 p.m.

1 stop7h 41m

Denver Intl

Wed 14/10

12:59 a.m.-10:24 a.m.

1 stop7h 25m

C$ 596

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Thu 17/9

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

1 stop16h 40m

Denver Intl

Mon 21/9

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

1 stop29h 35m

C$ 603

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Wed 29/7

7:24 p.m.-11:27 p.m.

1 stop6h 03m

Denver Intl

Sun 2/8

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

1 stop5h 56m

C$ 606

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Thu 27/8

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

1 stop16h 40m

Denver Intl

Sat 29/8

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

1 stop29h 35m

C$ 619

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Sat 11/7

1:00 p.m.-11:49 p.m.

1 stop12h 49m

Denver Intl

Sat 18/7

6:05 p.m.-11:17 p.m.

Nonstop3h 12m

C$ 622

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Tue 7/7

11:40 a.m.-8:43 p.m.

1 stop11h 03m

Denver Intl

Thu 9/7

1:10 p.m.-11:58 p.m.

1 stop8h 48m

C$ 622

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

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

How long is the flight to Boulder?

On average, a flight from Toronto to Boulder takes 11 hours 27 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 Wednesday, which is when the least amount of flights are scheduled (9 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$ 155
United Airlines
United Airlines
From C$ 190
WestJet
WestJet
From C$ 183
Delta
Delta
From C$ 142

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 12 June 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
9,810 reviews
Check prices

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Boarding

7.7

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
9,810 reviews
United Airlines
7.4
Good
9,810 reviews
Check prices

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Boarding

7.7

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
3,357 reviews
United Airlines
7.4
Good
9,810 reviews
Check prices

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Boarding

7.7

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
11,168 reviews
United Airlines
7.4
Good
9,810 reviews
Check prices

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Boarding

7.7

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$ 144, however they can be found for as little as C$ 110.

  • Where does the fastest flight to Boulder depart from?

    For those looking to save time traveling to Boulder, Vancouver offers the quickest one-way flight (1 hour 53 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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