C$ 145 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 21/9. 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

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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

Wed, 13 Aug - Wed, 20 Aug
Air Canada Logo
12:00 p.m. - 7:30 p.m.YYC-DEN
7h 30m1 stop
Air Canada Logo
7:05 p.m. - 12:43 a.m.DEN-YYC
5h 38m1 stop
C$ 230Air Canada
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Tue, 22 Jul - Tue, 29 Jul
WestJet Logo
8:55 a.m. - 11:27 a.m.YYC-DEN
2h 32mdirect
WestJet Logo
12:15 p.m. - 2:45 p.m.DEN-YYC
2h 30mdirect
C$ 235WestJet
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Sun, 20 Jul - Mon, 21 Jul
United Airlines Logo
6:15 a.m. - 8:49 a.m.YYC-DEN
2h 34mdirect
United Airlines Logo
7:19 p.m. - 9:48 p.m.DEN-YYC
2h 29mdirect
C$ 239United Airlines
Find Deal
Wed, 13 Aug - Wed, 20 Aug
Air Canada Logo
12:00 p.m. - 7:30 p.m.YYC-DEN
7h 30m1 stop
Air Canada Logo
7:05 p.m. - 12:43 a.m.DEN-YYC
5h 38m1 stop
C$ 248Air Canada
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Tue, 16 Sep - Tue, 23 Sep
WestJet Logo
8:55 a.m. - 11:24 a.m.YYC-DEN
2h 29mdirect
WestJet Logo
12:15 p.m. - 2:45 p.m.DEN-YYC
2h 30mdirect
C$ 272WestJet
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Tue, 16 Sep - Tue, 23 Sep
Delta Logo
6:40 a.m. - 3:44 p.m.YYC-DEN
9h 04m1 stop
Delta Logo
7:10 a.m. - 11:39 a.m.DEN-YYC
4h 29m1 stop
C$ 308Delta
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Mon, 15 Sep - Sat, 1 Nov
United Airlines Logo
6:15 a.m. - 8:42 a.m.YYC-DEN
2h 27mdirect
United Airlines Logo
11:20 a.m. - 1:56 p.m.DEN-YYC
2h 36mdirect
C$ 328United Airlines
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Tue, 12 Aug - Tue, 19 Aug
Delta Logo
8:55 a.m. - 11:27 a.m.YYC-DEN
2h 32mdirect
Delta Logo
12:15 p.m. - 2:46 p.m.DEN-YYC
2h 31mdirect
C$ 369Delta
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Fri, 8 Aug - Fri, 15 Aug
Alaska Airlines Logo
3:30 p.m. - 11:59 p.m.YVR-DEN
7h 29m1 stop
Alaska Airlines Logo
11:33 a.m. - 6:17 p.m.DEN-YVR
7h 44m1 stop
C$ 409Alaska Airlines
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Fri, 8 Aug - Fri, 15 Aug
Alaska Airlines Logo
3:30 p.m. - 11:59 p.m.YVR-DEN
7h 29m1 stop
Alaska Airlines Logo
7:11 p.m. - 9:38 a.m.DEN-YVR
15h 27m2 stops
C$ 425Alaska Airlines
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Useful Info

Good to know – Book Cheap Boulder Plane Tickets

Low seasonJanuary
High seasonAugust
Cheapest flightC$ 145
Best time to beat the crowds but there is an average 12% increase in price.
Most popular time to fly and prices are also 21% 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 Edmonton2h 45m
    Flights from Montreal4h 01m
    Flights from Vancouver3h 00m
    Flights from Toronto3h 26m
    Flights from Calgary2h 30m
  • 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$ 313 return. The most popular connection is from Toronto to Denver and KAYAK users have found round-trip deals for as low as C$ 434 in the last 3 days.

  • Which airlines fly to Denver?

    Many airlines fly to Denver, the most common ones being United Airlines, Air Canada, and WestJet. See the amount of flights per week for popular airlines flying to Denver.

  • 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 Winnipeg C$ 757, from Calgary C$ 1,185, from Vancouver Intl C$ 1,274
  • 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 10000 reviews
7.1Entertainment
7.8Comfort
8.5Crew
7.1Food
8.1Boarding
Airline reviews

Flight was delayed which led to missed connection, but rebooked on a more direct flight at the last minute and arrived in Juneau on time with all our luggage. Little stressful and our family seating got split, but it all worked out in the end.

10.0 ExcellentJeffrey, Jun 2025HNL - KOA
Read more Alaska Airlines reviews

Flight was delayed which led to missed connection, but rebooked on a more direct flight at the last minute and arrived in Juneau on time with all our luggage. Little stressful and our family seating got split, but it all worked out in the end.

It was very good and comfortable, Crew was also great

The flight was delayed almost an hour. No wifi on flight.

Terrible customer service, closed check in hours before flight left, provided incorrect information

Good experience, although it was a little cramped being a tall person. Otherwise everything went smoothly and professionally though

We have always flown with Alaska when we can. As they have great customer service. This trip we had to transfer to Air LINGUS in Denver to go to Dublin. That’s where things went bad! Our checked luggage didn’t arrive. The process to make a claim was way more complicated than it should be. It took 5 days to recover our luggage. The whole time we couldn’t talk to a real person who could tell us anything. The whole time Alaska blamed Air lingus and vis a versa. No one seemed want to help us. That was the worst part.

We were delayed. We spent more time waiting on the plane than actually flying (it’s only a 37 minute flight). Other than that, it was fine.

The setting on the loudspeaker was painful and the crew member who did the talking spoke very quickly and repetitively, with extra little jokes that were distracting and mostly unfunny. I doubt that the main messages penetrated the noise.

Only offered water, no snacks provided, and it was cold on the plane, everyone was wearing sweatshirt or jacket in June. I asked for blanket, but crew said they didnt have anything and would turn the heat up, that didn't happen, so for 6 hours I remained cold.

Delay of more than 3 hours I didnt recieve neither a voucher for food Attention disaster

Crew was excellent. Comfort seats not as nice as other kinds of planes.

Not a "Delta" issue, but a JFK issue: We booked a connecting flight with 3 1/2 hours between to clearn immigration and customs. Our inbound flight (BCN to JFK) was on the taxiway 45 minutes which ate into our layover time. Immigtration was insanely quick with the CBP MPC app; however, clearing TSA (again, after we were ALREADY cleared in Spain on the inbound international flight) took over 95 minutes. This left us with 10 minutes before boarding the connecting flight (JFK to SAN) to walk to the far end of Terminal 4 and try to find food. We didn't find any food that could promise to serve us in under 10 minutes so we boarded the Delta flight after coming off a plance and an 8-hour flight knowing that we wouldn't be served any food on the next 5 1/2 hour flight. I feel like Delta needs to put pressure on the JFK TSA to open more screening stations (by our count, we saw only 5 scanners open and a line of - as we said - over 90 minutes. The insult is that we WERE ALREADY SCREENED through TSA, but as you come off one flight into the USA, you have to go through the whole process again. It seems like if you have a connecting flight, there should be a way to pass through immigration and customs without needing to return through TSA.

The way BCN airport handled boarding was a huge improvement over our trip to Spain from JFK. Instead of gate-mosquitos edging in before their zone was called, in BCN they had clearly marked lines for Zones 1-8 and people just lined up correctly. The flight itself was uneventful. The meal (curried chicken and rice) was one of the better meals we've had on Delta. Entertainment options were plentiful, power chargers were available in Main Cabin, and seats were decent. Flight staff were very friendly and positive throughout the 8 hour flight.

It was a great flight and the stewards and stewardess were all kind and accommodating!! The seats were comfortable and entertainment screen excellent!

The checkpoint hornets are always looking fhrough Americans' luggage keeping what they deem impassible! Grrrrr!

There are 4 flights in consecutive gates with about the same departure time. Two flights were boarding at the same time. One was delayed or boarding would be happening at the same time. I am not sure what Delta and LAX need to do to have a better layout at the end of Terminal 2

Flight was an hour late, who knows why. It was OK, nothing outstanding.

Only not having an assigned seat was an issue. Rest was great

There was a security issue at the airport and we were unable to land. We circled endlessly and then landed at another airfield for fuel. We then circled the airport again, almost landed but didn’t fully touch down before circling again. I am thankful to the crew for keeping us safe- the issue was the airline and staff at the airport getting us seats on our connecting flights. That part was hours of searching for someone and getting in double my steps.

Boarding was organised and relaxed. Crew were fantastic! Seats were lacking padding causing butt pain and stiffness.

Very rough getting into denver. my kid threw up it was so rough.

Why wasn't this flight departure scheduled eith another crew so that it could leave on time? When we arrived in Denver we had so little time between flights we had run to the connecting flight. We should received some credit for the inconvenience.

Efficient, calm when things were delayed and kept us regularly informed of what was happening.

I was supposed to be on business class at first class from Denver back to Miami due to weather changes. I missed my connection and it’s put on a flight to Fort Lauderdale. Instead of honoring my business class/1st class ticket, they put me in coach, but there were two first class seats open. I think it’s absolutely disgusting that I paid for first class $1300 ticket and they put me in economy and they had to open seats available and I have still not been refunded the difference. I ended up having to eat a snack box instead of the meal I was supposed to get and did not get home till 2 AM so I think that’s a little pathetic that I had to live off crackers for dinner And my poor dog ate some cheese and salami. Oh yes, apparently when they switched me to the new flight they forgot to mention I had a service dog

Excellent service despite turbulence during the flight. Flight attendants were remarkable!

Flight attendant moved my bag without notifying me and was rude to me when I asked him about it. There was no reason to move it.

The gate attendant let me walk right by her with a bag too big for the overhead compartment

Plane temperature was comfortable (not to hot) when boarding and waiting for takeoff.

Food choices were very limited. Taste of the dishes was average.

I liked all the informational texts. I always knew where to go and when .

WestJet canceled my booking, replaced it with a booking that didn't work (departing from cruise ship), and didn't offer any flights that did work. Their only option was for me to cancel and go to another airline for more money. Which I did.

Nothing to like because my inbound flight was cancelled without notification by West Jet or third party, JustFly. I couldn’t take the inbound flight due to cancellation; therefore could not take the outbound flight back.

The seats are totally uncomfortable making the flight less than pleasant. The cookies & pretzels were terrible!!!

Late departure, so I missed connection in Detroit. But Delta gave me a great hotel & breakfast. Just sorry I could not get anything from my checked baggage.

Crew was friendly. Lost our luggage and told us it’d be in later in the evening of the day we returned. It was not. Still after 5 days have not received it.

Internet on both flights was sketchy. Thus in flight entertainment was non- existent on MN - Balrimote leg.

It took 30 minutes to check in with the Westjet rep. They didn’t have enough seats and she needed to make a call… I am always “randomly” selected to be checked at security. Their “randomly “ selection system may need some updating. They treat people like criminals. It is not appropriate behavior.

Will never book through you again. Very disappointed in the notices and action taken or provided when planes are rescheduled, enough to cause missed connections

Lost my luggage. Filed a report and there is no response. Received a phone call from another airline that said they had the bag and they did not know what to do with it

Very good over all , would have been nice to have entertainment on the flight

In a nutshell, my bag, the one I have to pay for, because now you can’t even bring a carry on, did not make it. I am still waiting for an update. The fact that not only were have to pay for it, but on top of that we are stuck without getting it, it’s ridiculous..

The plane was filthy!!!! There were empty food wrappers in the pockets and worst of all a wad of hair where someone had obviously brushed their hair, cleaned out the brush and left the wad of hair in the pocket. It was the most disgusting thing I’ve ever seen!! The seats are so crammed together with NO leg room. The AC vent controllers do not adjust. I will likely not book another AC flight from Florida to Montreal.

This was an excellent experience for a very short flight.

Registered my luggage at 5pm. Arrived at JFK at 1:00 am. Worst trip ever. Never again

Really good, super comfy flight and the stewardess was great.

Air Canada never runs on time. You’re lucky if your flight is not cancelled or diverted. Worst airline in the world for gas lighting its customers.

No space in overhead bin, one cookie, 2 oz of juice - is not customer service.

Good flight, friendly crew and overall - good service on United Airlines.

Received email saying that there won’t be a seat back entertainment screen and inflight WiFi would be available. But no WiFi both ways. Say it in the email.

Somebody either kayak or Air Canada booked my flight under my preferred name Betty instead of my legal name and I almost was denied boarding my flight

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