Find cheap flights to Boulder from $27
This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight departing on 10/19. 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.Round-trip
1 adult
Economy
Sat 10/21
Sat 10/28
In the last 7 days travellers have searched 45,131,337 times on KAYAK, and here is why:
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Good to know
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 tickets to Boulder for the following prices or less: From Miami $78 one-way - $113 round-trip, from Los Angeles $147 one-way - $185 round-trip, from Boston $164 one-way - $206 round-trip
- Book at least 1 week before departure in order to get a below-average price.
- High season is considered to be June and July. The cheapest month to fly from United States is January.
- Enter your preferred departure airport and travel dates into the search form above to unlock the latest Boulder flight deals.
FAQs - booking Boulder flights
How long is the flight to Boulder?
Flights from San Francisco 2h 44m Flights from Boston 4h 22m Flights from Dallas 2h 09m Flights from Portland 2h 44m Flights from Minneapolis 2h 08m What is the cheapest flight to Denver?
If traveling to Denver, the cheapest city to fly from in the last 3 days was Dallas, with flights as low as $27 one-way and $29 round-trip. Flights from San Francisco are the most searched and start at $58 for a return trip.
Which airlines fly to Denver?
Air Canada, Avianca, and Emirates usually have the most frequent connections from United States to Denver
How to fly to Boulder?
You cannot fly directly to Boulder. KAYAK recommends you fly to Denver Intl (DEN) (33.41 miles 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) (33.41 mi). Another nearby airport is Colorado Springs (COS) (88.84 mi). KAYAK recommends you fly to Denver Intl.
How far is Denver from central Denver?
The city center of Denver is 18 miles from Denver.
What is the name of Denver’s airport?
Denver is served by Denver, also commonly referred to as Denver or Denver Intl. The airport code is DEN.
Which airlines have a flexible cancellation policy for flights to Boulder due to COVID-19?
United Airlines, Air Canada and Southwest have waived their change and cancellation fees on flights to Boulder. Confirm policies on booking site.
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 travelers 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 5 airlines flying to Boulder
8.1
JetBlueOverall score based on 19464 reviews
86crew
83boarding
82comfort
82overall
79entertainment
78food
Airline reviews
Pros: "The crew was very friendly"
Cons: "Boarding. No clear lines. Everyone is all over the place."
Pros: "The crew was very friendly"
Cons: "Boarding. No clear lines. Everyone is all over the place."
Cons: "The tray tables were absolutely filthy when we put them down for our drink service. They were sticky and there was crumbs stuck to the back of the seat where the tray table. One of the flight attendants was incredibly frantic from boarding to in-flight service. She counted passengers 4 times and kept putting up her finger when passengers tried to get her attention."
Pros: "The crew! The pilot that looked like and introduced himself as Bob Newhart was funny!"
Cons: "The plane A320 is looking old and the seat cushion are flat as a pancake. No support"
Cons: "Cleanliness. Folding tray was dirty and smeared with god know what and there was food lying on the floor when we got in."
Pros: "absolutely nothing"
Cons: "Not being lied to repeatedly by ground crew, cabin crew pilots. We were being updated by the app 30 minutes before they told us anything never mind the truth. they managed to serve 7 rows of drinks the entire flight. by far the worst experience I have had in many years and I fly over 250,000 mile"
Cons: "Boarding took a long time. We were waiting in the tunnel for longer than usual."
Cons: "More complimentary food options given it’s a 6 and a half hour flight."
Pros: "I loved the plane itself with 2 seats on each side, so that each person can have either an aisle or window seat. They allowed my mother and I to board early due to her use of a cane to walk. The flight was on time."
Cons: "The sound quality to watch TV was terrible."
Pros: "Not much"
Cons: "1.5 hr mechanical delay caused missed connection and subsequent 7.5 hr layover -- no compensation .. I asked"
Pros: "Natalie was not pleasant I asked a question and she ignored my questions"
Cons: "I aske Natalie if there were any sit available so that my husband and I can sit together she quickly responded with out looking in the computer"
Pros: "Boarded plane back to front once Priority members boarded. Overall staff and Pilots were great. A quick flight of 75 minutes. Tea, coffee or water provided along with a small snack. Smooth flight and only minor delays which were handled in a timely manner."
Cons: "Flight delayed 3 hours, then a seats were very cramped and uncomfortable"
Cons: "Everything was fine... I should have packed a snack because I’m always hungry! Will travel Delta again!"
Pros: "Smooth, efficient and timely."
Cons: "Seats weren’t assigned until at the gate even though checked in 18 hours before. Bag drop was horrible. No self service. Was inline for about 45 minutes."
Cons: "Boarding process was really poor. Long line for just dropping a bag off that I already paid for."
Pros: "Crew was wonderful! Food was good. It was a good experience."
Cons: "This whole paying for comfort seats is annoying. Just make all the seats decent for all travelers."
Pros: "The fact that we left on time given the thunderstorms in the area, and landed on time in Atlanta was amazing. Congratulations to the crew!"
Cons: "Not surprised there was no WiFi, but it would have been nice as more aircraft of all sizes are now equipped with WiFi."
Pros: "The crew was helpful and seemed genuinely nice. The seats felt a little narrow"
Cons: "Plane was way too hot and stuffy, wasn't until about 20 min into flight before started to cool down."
Pros: "Delta cramps people into these planes and forces you to put your bags under a seat because they stuff at the overhead spaces. They nickel and dime you for every single thing. There was even one person I saw who had to pay for his headphones to listen to the onboard entertainment. I think Delta should quit being so cheap with the profits they make and give it back to your flying customers. It borders on gouging."
Cons: "Delta cramps people into these planes and forces you to put your bags under a seat because they stuff at the overhead spaces. They nickel and dime you for every single thing. There was even one person I saw who had to pay for his headphones to listen to the onboard entertainment. I think Delta should quit being so cheap with the profits they make and give it back to your flying customers. It borders on gouging."
Pros: "First of I would like to give a big THANK YOU to Parnel at JFK airport. He was such a big help. And his customer service was excellent."
Pros: "Nothing."
Cons: "All of it except the flight crew. They were from Hungary and very polite and helpful. The rest of my experience was terrible. Will not fly UNAmerican again. Will NEVER fly to or via DFW again."
Pros: "The ground crew is helpful in fixing our seats. Boarding procedures are smooth and overall journey is comfortable"
Cons: "the airline can provide more options for us to selecting seat at self help counter. Provide options for food. There are 2 vegan meals out of 3"
Pros: "The attendant for my area was amazing. I was in the back of the plane and he was friendly. He helped me look for my power cord. He is an outstanding member of your team!"
Cons: "Nope, this was a great flight!"
Pros: "nice flight attendant"
Cons: "had to board and squeeze into a bus to ride out to the plane. Had to stand for a really long time waiting for all passengers to gert on bus"
Pros: "Service was great in 1st class"
Cons: "The movie Black k Klansman was great but the system had a problem. Not sure if just my seat or the whole digital video system. Every few minutes it would get choppy and unwatchable. I had to rewind and then it would be fine for a while. Like a video buffering problem."
Cons: "There was a maintenance issue on departing plane which delayed us a few minutes and when we arrived to layover airport (note we still arrived before the connecting flight was scheduled to leave), the connecting flight had decided to leave early and was gone. Now stranded with standby and all the flights for the next few days are sold out. Beyond angry!"
Pros: "punctual and crew was very nice"
Cons: "old aircraft so each seat didn't have individual screens for entertainment"
Pros: "Overhead bins were newly done with plenty of space since carryon can be placed vertical on side. Decide holder built into the seat was very nice."
Cons: "Because our first flight was delayed over 4 hours we missed our connection and had to be re-booked on the only other flight that still had seats that day. We had previously booked and paid for Main Cabin extra seats in the second row that included extra leg room and free drinks. We ended in an airplane with two exit rows, one near the front and the other near the back. Our seats were right behind the rear exit row in the back of the plane. The seats did not recline and there was limited leg look because the exit row seats were aligned differently due to the crew seat next to the door. Also, the bathroom was right in front of the row in front of us and so it was busy, noisy and smelled. Obviously we didn't get our free drinks either. Now I'm having to fight with American trying to get a refund of the money we spent for the Main Cabin extra fees. The fun never stops. I will never fly American again."
Pros: "Crew was awesome. Super proficient and even threw in some extras to top off the experience."
Cons: "Has a minor delay due to air craft maintenance, but otherwise things went swimmingly."
Pros: "Nothing"
Cons: "If flights was on time I would not have to miss connecting flight in Dulles I had to stay for 22 hours in Indianapolis to be rerouted"
Pros: "Crew & flight attendants very courteous and apologetic; complisnacks while waiting for delayed flight"
Cons: "Flight delay!!"
Pros: "Crew, pilot were courteous"
Cons: "Inexcusable legroom In future will stick with JetBlue or Southwest"
Pros: "Brought my own entertainment. Friendly staff. Great boarding process. On time departure"
Cons: "Lufthansa as an agent is a mistake! I had to deal with them prior to flying to the US. I have never ever had to deal with such bad service in my entire life. United was great though and I highly recommend them."
Cons: "we paid for 2 seats together in economy plus, but due to an equipment change, we were split up. In order to sit together we were downgraded to economy. It would have been nice if they had informed us when the change occured so we could have made arrangements"
Cons: "My flight was delayed 5hrs and added multiple connecting flights that I didn’t need. I had a 6am flight and didn’t get to my destination until 11pm."
Pros: "I didn’t like anything at all. I called the 1-888 number the change my flight and it was a survey questionnaire. I missed my flight and I end buying another one this site is a joke"
Cons: "Nothing"
Cons: "Old plane even though we upgraded to first class it was just bigger seats no entertainment cold draft just horrible felt like we were flying back in the 80s. Lastly our luggage didn't come with our flight it came with the next flight. Horrible horrible experience"
Pros: "On time and quick flight"
Cons: "Don't nickel and dime us for everything! Ads were deceptive and the price ended up being much more expensive after paying for bags, seats and carry on!!"
Pros: "Friendly crew!"
Cons: "Cramped up like sardines on plane! No room or reclining chairs!"
Pros: "Crew did fairly well under the circumstances. Clean aircraft."
Cons: "4 hour delay because frontier either doesn’t contract for or refuses to pay for deicing services in Phoenix. The pilot stated that Sky Harbor doesn’t have deicing services which I personally know to be false because southwest and delta both have deicing services and their is a deicing location at the airport. Instead we waited for the sun to thaw the airplane and further waited for a fuel truck afterwards. Only the first three rows have reclining seats that you pay extra for. I only recommend frontier for SHORT commutes, as the seats really are that uncomfortable with very little padding. NEVER AGAIN!"
Pros: "Pilot kept us posted on details about a few minutes delayed, very professional"
Cons: "Overall good flight!"
Pros: "They charge you for everything nothing is complimentary . The seats are super uncomfortable. No tvs can't recline. They want you to think your saving So much because the ticket is cheap but they end up charging you for literally everything else. They charge you for everything nothing is complimentary . The seats are super uncomfortable. No tvs can't recline. They want you to think your saving So much because the ticket is cheap but they end up charging you for literally everything else."
Cons: "They charge you for everything nothing is complimentary . The seats are super uncomfortable. No tvs can't recline. They want you to think your saving So much because the ticket is cheap but they end up charging you for literally everything else. Not worth it at all!!!"
Cons: "I was forced to pay for my carry-on which was the same price as the check in bag. The complimentary drink and nuts were a charge and I missed my layover flight because they did not announce it. I want my money back! I had to get a whole new ticket from a different airline."
Pros: "i was at the gate to get on the plane. there was two minutes left before they were supposed to close the doors for take off wouldnt let me on the plane. i had to set there for over 15 minutes with the plane on the ground trying to figure out how to get to my destination. the attent was trying to help but then left there post before i could figure out what to do. totally unacceptable due to me being a minor and not aiding and assisting to the fullest. i had to leave the airport without a way to my destination because everyone left all posts all three gates and the baggage check in area was closed for over 5 hours. my father had to call and get me on the next available flight. they charged him a 100 dollar fee for changing my flight."
Pros: "Boarding was organized and efficient. Overhead storage was adequate and flight attendants kept an eye on appropriate use of the overhead bin (i.e. used for those passengers sitting underneath or across the aisle). Plane was absolutely on time. Captain relayed weather warning about bumpiness appropriately."
Cons: "Be prepared for bare-bones economy seating unless you want to pay $45 more for what used to be regular seating that reclines."
Cons: "Old uncomfortable seats. 4 hour flight with no tv. Flight was delayed with no explanation why."
Pros: "The plane boarded and left on time and arrived on time."
Cons: "Almost everything! I chose this flight because of the price. However, upon check-in, there were three big extras : checked bags were $40 each, and any carry-on that could not fit below a seat was another $45! The icing on the cake wss that we had to pay for seats. The cheapest were an additional $5 each, and seats up front were $15 (although these were no different from those in the rear of the plane.) When we landed, the flight attendant announced that we were 20 minutes early and that we needed to "remember that the next time when we are 20 minutes late." As it turned out, we could not deplane for another 20 minutes anyway. I will not fly this airline again."
Book Cheap Boulder Plane Tickets
Recent round-trip flight deals
11/1Wed
nonstopFrontier
2h 22mONT-DEN
11/7Tue
nonstopFrontier
2h 24mDEN-ONT
$29
10/18Wed
nonstopFrontier
2h 16mDFW-DEN
10/25Wed
nonstopFrontier
2h 06mDEN-DFW
$31
11/8Wed
nonstopFrontier
2h 22mONT-DEN
11/11Sat
nonstopFrontier
2h 31mDEN-ONT
$31
10/18Wed
nonstopFrontier
2h 16mDFW-DEN
10/21Sat
nonstopFrontier
2h 06mDEN-DFW
$38
11/1Wed
nonstopFrontier
2h 11mDFW-DEN
11/7Tue
nonstopFrontier
2h 02mDEN-DFW
$40
10/18Wed
nonstopFrontier
2h 22mONT-DEN
10/25Wed
nonstopFrontier
2h 31mDEN-ONT
$40
10/18Wed
nonstopMultiple Airlines
2h 16mDFW-DEN
10/25Wed
1 stopMultiple Airlines
10h 42mDEN-DFW
$57
10/31Tue
1 stopSpirit Airlines
7h 13mLAX-DEN
11/7Tue
1 stopSpirit Airlines
4h 54mDEN-LAX
$59
10/2Mon
1 stopSpirit Airlines
10h 50mSEA-DEN
10/4Wed
1 stopSpirit Airlines
13h 29mDEN-SEA
$68
10/4Wed
1 stopSpirit Airlines
4h 59mLAX-DEN
10/11Wed
1 stopSpirit Airlines
11h 21mDEN-LAX
$68
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10/19Thu
nonstopFrontier
2h 14mDFW-DEN
$27
10/11Wed
nonstopFrontier
2h 38mSFO-DEN
$29
10/11Wed
nonstopFrontier
2h 51mSEA-DEN
$29
10/3Tue
nonstopFrontier
3h 24mATL-DEN
$29
9/27Wed
1 stopSpirit Airlines
11h 10mLAX-DEN
$31
10/17Tue
nonstopFrontier
2h 38mSFO-DEN
$31
10/3Tue
nonstopFrontier
2h 54mSEA-DEN
$31
11/8Wed
1 stopSpirit Airlines
8h 42mLAX-DEN
$34
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11h 31mSEA-DEN
$35
10/1Sun
1 stopMultiple Airlines
20h 46mLAX-DEN
$42
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9/26Tue
multi-stopSpirit Airlines
11h 31mSEA-DEN
10/3Tue
multi-stopSpirit Airlines
7h 00mDEN-SEA
$66
9/26Tue
multi-stopMultiple Airlines
11h 31mSEA-DEN
10/3Tue
nonstopMultiple Airlines
3h 03mDEN-SEA
$67
9/26Tue
nonstopFrontier
2h 54mSEA-DEN
10/3Tue
nonstopFrontier
3h 00mDEN-SEA
$68
9/26Tue
nonstopFrontier
2h 15mDFW-DEN
10/3Tue
nonstopFrontier
2h 02mDEN-DFW
$70
9/26Tue
multi-stopMultiple Airlines
8h 19mDFW-DEN
10/4Wed
nonstopMultiple Airlines
2h 04mDEN-DFW
$71
9/26Tue
nonstopFrontier
2h 41mSFO-DEN
10/3Tue
nonstopFrontier
2h 47mDEN-SFO
$78
9/26Tue
nonstopFrontier
2h 35mSEA-DEN
9/30Sat
nonstopFrontier
3h 01mDEN-SEA
$78
9/26Tue
multi-stopFrontier
7h 04mDFW-DEN
10/3Tue
nonstopFrontier
2h 02mDEN-DFW
$80
9/26Tue
multi-stopSpirit Airlines
12h 16mLAX-DEN
9/29Fri
multi-stopSpirit Airlines
12h 37mDEN-LAX
$83
9/26Tue
multi-stopFrontier
5h 38mSFO-DEN
10/3Tue
multi-stopFrontier
6h 23mDEN-SFO
$83
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