C$ 135 Find Cheap Flights to Boulder

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Boulder departing on 9/12. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
C$ 204
Overall average: C$ 585
Air Canada
Thu 15/1Sun 18/1
YYC - DEN • 1 stop
Cheapest direct flights
C$ 205
Typical prices: C$ 467-C$ 881
United Airlines
Sat 17/1Sun 18/1
YYC - DEN • Direct
Top routes
YYC-DEN
Cheapest
YVR-DEN
Most popular
Insights
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Flight Deals
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Flight Deals

Cheap Flights to Boulder

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights to Boulder that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals to Boulder

Thu, 15 Jan - Sun, 18 Jan
Air Canada Logo
6:00 a.m. - 12:37 p.m.YYC-DEN
6h 37m1 stop
Air Canada Logo
8:05 a.m. - 1:55 p.m.DEN-YYC
5h 50m1 stop
C$ 204Air Canada
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Sat, 17 Jan - Sun, 18 Jan
United Airlines Logo
2:13 p.m. - 4:45 p.m.YYC-DEN
2h 32mdirect
United Airlines Logo
7:15 p.m. - 9:53 p.m.DEN-YYC
2h 38mdirect
C$ 205United Airlines
Find Deal
Thu, 15 Jan - Sun, 18 Jan
Lufthansa Logo
2:13 p.m. - 4:45 p.m.YYC-DEN
2h 32mdirect
Lufthansa Logo
7:15 p.m. - 9:53 p.m.DEN-YYC
2h 38mdirect
C$ 213Lufthansa
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Thu, 15 Jan - Sun, 18 Jan
Air Canada Logo
6:00 a.m. - 12:37 p.m.YYC-DEN
6h 37m1 stop
Air Canada Logo
7:15 p.m. - 9:53 p.m.DEN-YYC
2h 38mdirect
C$ 236Air Canada
Find Deal
Fri, 16 Jan - Sat, 31 Jan
Air Canada Logo
6:00 a.m. - 12:37 p.m.YYC-DEN
6h 37m1 stop
Air Canada Logo
8:05 a.m. - 7:44 p.m.DEN-YYC
11h 39m1 stop
C$ 246Air Canada
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Wed, 21 Jan - Sun, 25 Jan
Alaska Airlines Logo
1:01 p.m. - 11:35 p.m.YYJ-DEN
9h 34m1 stop
Alaska Airlines Logo
7:00 a.m. - 12:11 p.m.DEN-YYJ
6h 11m1 stop
C$ 334Alaska Airlines
Find Deal
Wed, 28 Jan - Sun, 1 Feb
Alaska Airlines Logo
6:09 a.m. - 12:38 p.m.YYJ-DEN
5h 29m1 stop
Alaska Airlines Logo
7:00 a.m. - 12:11 p.m.DEN-YYJ
6h 11m1 stop
C$ 335Alaska Airlines
Find Deal
Sun, 11 Jan - Sun, 18 Jan
United Airlines Logo
9:45 p.m. - 12:26 p.m.YYJ-DEN
13h 41m1 stop
United Airlines Logo
11:46 a.m. - 4:56 p.m.DEN-YYJ
6h 10m1 stop
C$ 365United Airlines
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Thu, 14 May - Sun, 17 May
WestJet Logo
6:45 a.m. - 11:25 a.m.YUL-DEN
30h 40m1 stop
WestJet Logo
12:15 p.m. - 12:42 a.m.DEN-YUL
10h 27m1 stop
C$ 442WestJet
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Fri, 1 May - Fri, 8 May
WestJet Logo
6:45 a.m. - 11:25 a.m.YUL-DEN
30h 40m2 stops
WestJet Logo
12:15 p.m. - 12:42 a.m.DEN-YUL
10h 27m1 stop
C$ 452WestJet
Find Deal
Useful Info

Good to know – Book Cheap Boulder Plane Tickets

Low seasonJanuary
Cheapest flightC$ 135
Best time to beat the crowds but there is an average 11% increase in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Calgary to Denver

Flights to Boulder: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew to Boulder 
JesseFlew with Air CanadaYVR-DENMay 2025
keep more time incase connecting flight, usually flights late
Verified travelerFlew with Air CanadaYVR-DENFeb 2025
Take as little carryon as possible. Expect small seats and overhead bins are not nearly as big as longhair flights. Restrooms are tiny as well.
Verified travelerFlew with United AirlinesYYC-DENAug 2024
Denver International is a really nice airport, but it should be for a hub! A lot of stuff is actually open until 10:30 or 11pm, so that’s nice. Pretty good place to do an overnight layover too…just make sure to get some snacks in case you can’t sleep.
F.Flew with United AirlinesYYZ-DENAug 2024
Make sure to check the airline delay flights rate and if you have important commitments choose another airline.
JoshuaFlew with Air CanadaYYZ-DENApr 2024
Toronto's customs was one of the faster experiences I've had. They opened four more lanes to expedite the process when the lane got too long, to ensure we would all get through within around 15 minutes. The public transportation within the city is also top notch, in my opinion.
VictoriaFlew with United AirlinesYYC-DENMar 2024
A tip I have is if you’re in a 4/5 boarding class you might want to check your bag ! There’s not enough room for everyone’s carryon above if it’s a full flight.
KimFlew with United AirlinesYEG-DENJan 2024
Completing your passport paperwork on line makes a smoother transition at the airport

FAQs - booking Boulder flights

  • How long is the flight to Boulder?

    Flights from Regina2h 37m
    Flights from Montreal4h 06m
    Flights from Toronto3h 32m
    Flights from Winnipeg2h 35m
    Flights from Calgary2h 35m
  • What is the cheapest flight to Denver?

    In the last 3 days, the cheapest flight deal to Denver was found on the route from Calgary, at C$ 204 return. The most popular connection is from Vancouver to Denver and KAYAK users have found round-trip deals for as low as C$ 257 in the last 3 days.

  • How to fly to Boulder?

    You cannot fly directly to Boulder. KAYAK recommends you fly to Denver Intl (DEN) (53.76 km from Boulder). From there you can rent a car or get a taxi.

  • What airports are near Boulder?

    The closest airport is Denver Intl (DEN) (53.76 km). KAYAK recommends you fly to Denver Intl.

  • How far is Denver Intl Airport from central Denver?

    There are 30 km between Denver downtown and Denver Intl Airport.

  • What is the name of Denver’s airport?

    When flying to Denver, you'll arrive at Denver Intl Airport (DEN). The airport is also known as Denver or Denver Intl.

  • How does KAYAK find such low prices on flights to Boulder?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights to Boulder.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket to Boulder?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Boulder is likely to change within 7 days, so travellers know whether to wait or book now.

  • What is the Hacker Fare option on flights to Boulder?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Boulder with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight to Boulder?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Boulder up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Top tips for finding cheap flights to Boulder

  • There is no major airport in Boulder. It is instead served by Denver Intl Airport.
  • Looking for cheap airfare to Boulder? 25% of our users found round-trip tickets to Boulder for the following prices or less: From Calgary C$ 439, from Winnipeg C$ 542, from Vancouver Intl C$ 651
  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest Boulder flight deals.

Reviews of the top 5 airlines flying to Boulder

 
Need help choosing which airline to fly with from Canada to Boulder? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 11373 reviews
8.1Boarding
7.8Comfort
7.1Food
8.5Crew
7.0Entertainment
Airline reviews

Leg and arm room are horrible. I am not a big person and found it tight.

10.0 ExcellentAnonymous, Nov 2025BOS - SEA
Read more Alaska Airlines reviews

Leg and arm room are horrible. I am not a big person and found it tight.

It was good except there was a loud rattle from the window on aisle 10 DEF,

The man next to us had a medical emergency a the flight attendants really stepped up and quickly helped turn a bad situation into one with a great outcome. Brandon, Ranger , and Jose all did wonderful jobs gathering all the medical field passengers on the plane to help (a my husband) and they helped revive the unresponsive patient within a few minutes with juice and oxygen. It was a great example of community and teamwork and I’m so impressed with the staff.

The ground crew did not supply drink or snacks during the layover in SFO. So there weren't many options. Otherwise, it was all great.

Had no way to see what gate came in on or what gate connecting flight would take off.

We flew economy, it was what I expected. The seats are too upright for me

No accommodation or credit offered for cancelled layover flight to Eugene from portland

If they loaded the back of the plane first, loading would go faster

accommodating myself, my dog and crate when the flight was delayed multiple times

I know airlines have to save money, but a little more legroom would be nice. I’m a small person and I just felt cramped after a few hours. However, I loved everything else! Free Alaska Airlines wifi, free movies, yummy snacks, and the crew was so helpful and accommodating!

Staff was exceptional! Everyone was kind, professional and friendly making the trip very pleasant. Thank you!

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

We had a lot of really rough weather but that was not Delta's fault. Pilot was amazing.

One of the best airlines that I flew on, the flight attendants were very attentive and professional.

First, Delta needs more flights to/from Miami. Second, a 1000pm leaving at 1230pm is unacceptable from their biggest airport world hub. Another aircraft could have been used such as the aircraft scheduled to be used in the morning for that exact same route. Yes, I did get me there but the lack of sleep the next day didn't help me enjoy my entire trip since I was busy with activities during the weekend. This can be and is expected from Spirit (going bankrupt) and Frontier (despite they're nickel and dimers). But from Delta's World Hub? That's totally unacceptable!

This flight was straightforward and without difficulty. Service was OK, but I continue to be underwhelmed by level of attention given to Sky Priority passengers.

It would’ve been nice for all that money to have a more substantial snack for free. I remember once upon a time getting a very nice turkey sandwich with Swiss cheese on whole wheat bread for no charge along with a drink. I guess those days are gone. it’s a little insulting being given a cookie or a bag of baked chips Going forward I’ll just bring my own.

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Service in business class was not impressive. I ordered coffee with dinner and then watched other people get 2 refills before I got my 1 cup of coffee, and only after I pressed the attendant button overhead. Furthermore, the seats in the forward cabin need maintenance on this 737-800: the upholstery is detaching from the seat frame, at least on the backs of seats 1C, 1D.

The ticket agents in West Palm Beach on Friday afternoon Nov. 7th were incredible in getting us on an earlier plane to Atlanta during the government shutdown. Had the taken our original flight we would have missed our connection. She did this on her own, We didn't even have to ask, and she did it all with a smile and showing genuine concern that we would be taken care of. We are very grateful and thankful. We fly often, and now we will be sure to fly Delta.

We Left Calgary 1/2 hour late and that made for a tight connection in Denver. After arriving everything was done to help us make our connection. That was a great effort. Thank You United

The entertainment available didn’t work for anyone on the flight. Long 6 hr flight with no entertainment option and the staff didn’t know until an hour into the flight when we made sure they knew about it. They had no way to fix it.

Late FA meant slow boarding. WiFi did not work. I’m a medium plus sized passenger. The seatbelt was for the first time ever barely fitting. And we delayed on the tarmac 40 min

My husband and I had boarded the flight from Denver to Chicago, and one of the last passengers to get on the plane opened the overhead bin above my husband's seat and threw his bag out of the bin to make space for his own. He said, "Mine is bigger!" The flight attendant supported the new passenger. They didn't care that my husband has two artificial knees and must have the foot room in front of his seat to be able to fit his legs in -- and to be able to stand, much less walk, at the end of the flight. I have never seen this happen before, and it was a disaster.

Terrible. They wouldn't allow me on my flight on the 14th..

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

Had to cancel first flight because Airporter Bus took over 3 hrs to get to airport which resulted in an extra $378 dollar fare . Is there anyway I can be reimbursed for initial fare since it was not my fault? Sent from my iPhone EJ Ledet

Excellent flight. Boarding was efficient and departure was on time. Smooth flight with on time arrival. Deplaning was also efficient.

Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.

I never flew. Flight was canceled. DIA worst airport in the country. Avoid at all costs.

I was seated near a "stinky" person. That's not the fault of Westjet🙁😶‍🌫️

Do not fly on WestJet if you have a connection. It failed to integrate with my connecting Delta flight and I almost missed it.

There was a man who was very rude at boarding. On the other hand personal bag measuring box is too small compared to USA airlines,

A little better seat cushions would be appreciated. Crews were all good.

The process and flight were both smooth and trouble free

Flight delayed 3 hours, missed my connection in Atlanta. Instead of getting to Savannah at 6PM arrived after 10:00PM Middle seat, couldn't get isle or window, couldn't book my seats in advance, had to book at the gate. That's a 1st for me and I used to travel a lot

my carry-on bag was delayed and I did not receive it until the day of my return at the airport. This delay caused me significant inconvenience, as I did not have access to my personal belongings for the duration of my trip. I had expected to rely on my carry-on items, and being without them negatively impacted my travel experience.

Technology issues at the bag-check counter caused a delay, and we were unable to check out our bags, ultimately missing our flight. They offered no assistance other than telling us to book another flight out of Calgary. We arrived with plenty of time; if there hadn't been an issue with the kiosk and the length of the lines due to the technical issues, we could have made it home.

Worst check in and bag drop off experience. Staff were incredibly rude given that it’s the WestJet system that is faulty.

The staff at the airport and on the plane were wonderful I especially wanna acknowledge the staff who boarded us at the Calgary airport. The women who helped us board at the airport were incredible… they were so kind and sweet…I very happy with WestJet and I am hoping I can fly more often to Canada.

3 hr delay at the gate while they were doing maintenance. Next time, do not board passengers while maintenance is being performed

Digital check in is very poor with air canada compaired to other airlines

Baggage delayed we had to catch our cruise without any clothes 😒

Air Canada Rouge is great. Toronto Airport is the usual nightmare

Good but need to be better with the flight times.

The staff could not have been any friendlier. Lots of usb ports on our aircraft.

The staff was great and made the long trip easy peasy!

Air Canada cancelled our flight and reschedule it 26 hours later that completely interrupted my family's long waited Japan trip, it wasn't due to natural reason such as weather but under the company's control. On the day we wasted 9 hours of our time from 6am to 3pm, including a few hours in the customer counter waiting for supervisor to handle our rescheduling. When we came to the counter for rebooking help there were at least 4 employees on the counter but we were told they were not trained to handle customer rebooking, we were also told the supervisor could come 10:30 to handle our rebooking, but she showed up more than one hour later, the end result was exactly the same so the few hours we spent waiting for her was completely wasted; We already prepaid hotel and all the tickets for the our stay in Tokyo so all of the cost for the first day is completed wasted; The $80 meal voucher issues was far less than our financial loss due to the financial cancellation, and it was not surprisingly invalid (as Your company screw up everything possible along the flight), the vouchers were supposed to last 72 hours, when we tried to used it at our lounge next day less than 24 hours from its issuing at a designated restaurant, the worker there couldn't scan the vouchers after multiple tries on all 4 vouchers issued, so we had to pay the food from our own money; For the two return flights they were also full of unfortunate events that caused bad experience and further delay and waste of our time, both flights departed late and the last leg had another significant delay of more than half an hour after touchdown, the gate was for some reason not available so we waited more than half an hour, when we got out of plane it was almost one hour later than the supposed arrival time; The gate you arranged is the farthest in Vancouver airport, also was the luggage pickup location in Seattle airport; We also called customer service for rescheduling help and after a long time wait (more than an hour) we got a call back but the CS representative was equally clueless and unhelpful. Other than a fatal crash, your company couldn't do anything right and provided the worst service possible among the tons of flights we have taken in our lives.

The free Wi-fi for Aeroplan members was a great touch. The time passed quickly. I found the seats seemed a little closer together than I remember. Not Air Canada's fault, but we were about 20 minutes late landing because the airport was too busy. We had to circle around for a while. The boarding and disembarking went very smoothly.

It was crazy, boarded over a hour late from scheduled departure. Then when arrived in BNA issued with getting off the plane…over 1/2 hour. Not looking forward to flying Air Canada, ever again.

Everything you need to know for your flight to Boulder