$59 Find Cheap Flights from Phoenix 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 from Phoenix to Boulder departing on 7/19. 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.
1 adult
1 adult, Economy

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Cheap Flights from Phoenix to Boulder (PHX-DEN)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Phoenix 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 from Phoenix to Boulder

Tue, Jul 15 - Tue, Jul 22
Frontier Logo
7:18 am - 10:15 amPHX-DEN
1h 57mnonstop
Frontier Logo
9:36 pm - 10:34 pmDEN-PHX
1h 58mnonstop
$116Frontier
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Thu, Aug 28 - Sun, Aug 31
Frontier Logo
3:03 pm - 6:06 pmPHX-DEN
2h 03mnonstop
Frontier Logo
7:15 pm - 8:14 pmDEN-PHX
1h 59mnonstop
$117Frontier
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Wed, Oct 29 - Sat, Nov 1
Alaska Airlines Logo
10:35 am - 7:03 pmPHX-DEN
7h 28m1 stop
Alaska Airlines Logo
12:49 pm - 10:16 pmDEN-PHX
10h 27m1 stop
$156Alaska Airlines
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Sat, Jul 19 - Tue, Jul 22
Southwest Logo
4:10 pm - 10:00 pmPHX-DEN
4h 50m1 stop
Southwest Logo
6:15 am - 7:10 amDEN-PHX
1h 55mnonstop
$183Southwest
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Wed, Jul 9 - Tue, Jul 15
 Logo
11:30 am - 4:35 pmPHX-DEN
4h 05m1 stop
 Logo
9:36 pm - 10:34 pmDEN-PHX
1h 58mnonstop
Wed, Aug 27 - Sun, Aug 31
Southwest Logo
3:15 pm - 6:00 pmPHX-DEN
1h 45mnonstop
Southwest Logo
8:50 am - 12:15 pmDEN-PHX
4h 25m1 stop
$187Southwest
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Mon, Jul 14 - Sat, Jul 19
 Logo
7:18 am - 10:15 amPHX-DEN
1h 57mnonstop
 Logo
1:50 pm - 5:30 pmDEN-PHX
4h 40m1 stop
Sat, Sep 13 - Mon, Sep 15
American Airlines Logo
3:20 pm - 6:07 pmPHX-DEN
1h 47mnonstop
American Airlines Logo
6:00 pm - 10:18 pmDEN-PHX
5h 18m1 stop
$195American Airlines
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Wed, Aug 27 - Sun, Aug 31
American Airlines Logo
8:33 am - 11:30 amPHX-DEN
1h 57mnonstop
American Airlines Logo
6:00 am - 11:26 amDEN-PHX
6h 26m1 stop
$202American Airlines
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Fri, Oct 17 - Sun, Oct 19
Alaska Airlines Logo
4:17 pm - 11:47 pmPHX-DEN
6h 30m1 stop
Alaska Airlines Logo
7:01 am - 3:17 pmDEN-PHX
9h 16m1 stop
$216Alaska Airlines
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Good to know

Low seasonJanuary
High seasonJuly
Cheapest flight$59
Best time to beat the crowds with an average 14% drop in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Phoenix Sky Harbor Airport to Denver

When to book flights from Phoenix to Boulder

Are your dates flexible? Find out the best times to travel from Phoenix to Boulder based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Phoenix to Boulder

  • Which airports will I be using when flying from Phoenix Sky Harbor Intl Airport to Boulder?

    When flying out of Phoenix Sky Harbor Intl Airport you’ll be using Phoenix Sky Harbor Intl. Boulder does not have its own airport so you’ll be flying into nearby Denver Intl airport, which is 33.4 mi away.

  • How long does a flight from Phoenix Sky Harbor Intl Airport to Boulder take?

    Direct flights cover the 601 miles separating Phoenix Sky Harbor Intl Airport and Boulder in about 1h 45m.

  • How many flights are there between Phoenix Sky Harbor Intl Airport and Boulder?

    36 direct flights run between Phoenix Sky Harbor Intl Airport and Boulder on a daily basis. On average, there are about 257 departures each week.

  • What’s the cheapest day of the week to fly between Phoenix Sky Harbor Intl Airport and Boulder?

    Consider leaving on a Tuesday and avoid Fridays if you are looking for the best rates. For your return to Phoenix Sky Harbor Intl Airport, you’ll find the best rates on Thursdays and the most expensive ones on Fridays.

  • How does KAYAK find such low prices on flights from Phoenix 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 from Phoenix to Boulder.

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

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

  • What is the Hacker Fare option on flights from Phoenix 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 to Phoenix with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Phoenix 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 from Phoenix up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Phoenix Sky Harbor Intl Airport to Boulder?

    In the last 72 hours, the cheapest one-way ticket between Phoenix Sky Harbor Intl Airport and Boulder found on KAYAK was with Frontier for $59. Frontier offered a round-trip connection from $116 and Alaska Airlines from $156.

Top tips for finding cheap flights from Phoenix Sky Harbor Intl Airport to Boulder

  • There is no airport in Boulder. Instead, you’ll be flying into Denver Airport when flying between Phoenix Sky Harbor Intl Airport and Boulder.
  • The cheapest flight from Phoenix to Boulder was found 48 days before departure, on average.
  • Book at least 2 weeks before departure in order to get a below-average price.
  • High season is considered to be April, May and June. The cheapest month to fly is February.

Reviews of the top 4 airlines serving Phoenix to Boulder

 
Need help choosing which airline to fly with from Phoenix 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
SouthwestOverall score based on 4279 reviews
7.6Entertainment
8.6Crew
7.1Food
8.2Boarding
8.0Comfort
Airline reviews

Southwest is typically delayed, and it gets wearisome. It is no longer a discount airline and you get way less than you pay for when it comes to comfort and Ce.

6.0 GoodDavid, Jun 2025BWI - COS
Read more Southwest reviews

Southwest is typically delayed, and it gets wearisome. It is no longer a discount airline and you get way less than you pay for when it comes to comfort and Ce.

We sat on the plane on the tarmac for 4 hours.

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

WiFi on the flight was not working. Thus, entertainment options were limited.

I really like open seating. I hate that I've heard this is going away. This is one of the unique things that makes Southwest my goto choice.

For the first time in a long time we had a flawless experience with Southwest. Both flights were early and no mechanical errors at all. We were shocked and pleasantly surprised 😮.

One of the crew performed a hilarious skit to accompany the standard instructions. Passengers enjoyed it so much they applauded at the end!

It was really nice! I appreciate the gate attendant allowing families with small children to board early on in the process… that was very helpful! The internet service didn’t work with the app I was trying to use even though I paid the $8… other than that it was great! Oh and I should’ve asked for the whole cranberry cocktail can. That cup was about 2 sips…

Delayed 4 hours due to mechanical issues. No mention of compensation for being over 3 hours late

At time of arrival to the airport, there were plenty of kiosks open/running for checking and baggage tags. While waiting to drop my bag, a team member was checking everyone's IDs against their baggage tag to verify a match/compliance to save additional time when dropping it at the front of the line. This was actually a really big time saver and greatly appreciated! Once boarding was starting, the team member had a clear and audible voice with their announcements, with direct (yet friendly) instructions for the boarding process. Once actually boarding, the flight crew gave genuine greetings while walking on board and were very nice and attentive during the flight. The take-off and landing were one of the smoothest I've had in MANY of years. Kudos to the pilots! I literally cannot remember the last time a had such a smooth landing :D

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

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 .

Received an email the night before showing that there would be seatback entertainment on our flight. We get on and there was no seatback entertainment. And then it was a scramble to try to set up the iPads for the kids before takeoff so they could watch something for the four hour flight.

The reason I don’t fly United. No in seat entertainment for a long flight and inconsistent WiFi and entertainment available from my device.

We were delayed 3x and because I didn’t purchase my tickets directly from United Airlines I was told I Have to take care of it myself so I called Underpricer and they helped me but before I changed my flights I took the risk of sticking by what my tickets were and was lucky to have gotten on the original all flight with only 15 mins before take off. not sure if I will do this again

It was a good flight. Nothing comes to mind about how it could have been better. It was a newer plane, seemed like a great upgrade from your older ones. Staff was very good as well.

Overall, a good experience. The food, however, was subpar. The breakfast was a joke.

First world problems, but still… We were seated in first class and asked for a cocktail on a very short, 50 minute flight. After our drink order was taken, a half hour went by, and we noticed that every other person in the small plane had been served except for us. We got up to ask about it, the drinks finally came, then were taken away three minutes later since the flight was so short. Really strange situation, on the other hand, we were in Utah.

Boarding took forever, the plane was cramped and cold, and the seatbelt song came on constantly throughout the red eye flight with a loud pre-recorded message playing each time

Wonderful crew and early arrival to our destination. It was so nice to have free wifi access and movies too. Thank you!

Bigger seats. Board back to front! Disembark front to back!

Plane was pretty clean, staff was friendly and helpful, flight left about on time arrived early. Took a long time to board and get off the plane - carry on items didn't have enough room so people had to move all around to find places.

Service in first class no longer exists on American Airlines .

My seat was very worn. Otherwise I had an excellent flight

Boarding can be more efficiently done by having the back row passengers board first. This way, the other people do the have to wait for front row passengers to load their luggage in the overhead cabins. Food is simply pathetic for the price I paid. Cleanliness is simply poor; my seat was full of crumps.

Always a great flight on AA. PHX to DFW and vise versa is always going to be a pretty full flight but the crew handles it phenomenally.

I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.

Seats are uncomfortable but price is good. Guess I can put up with misery for four hours.

The plane failed preflight inspection, so we sat there for 90 mins while they tried to fix it. Ultimately, everything was remedied and we made our connecting flight; instead of a 2 hour layover at the airport, we spent it waiting on the plane.

Early arrival. Great landing. Pilot updates. Too cold in plane.

My experience with the phoenix airport was terrible, the personnel lay the ticket counter charged me for a carry on that fit in the carry on size box, and the two women I spoke with were terribly rude and not willing to help.,,, there was one lady “candy” on the flight crew that was amazing and is the only reason I stayed on the flight at all, because the other stewards helping people to get seated on the plane were terrible

I loked walking out on the tarmac to board and no first class. I didn't like that they have no snacks or onboard wifi to bide your time.

The seats were extremely hard and uncomfortable. It was disappointing even for a budget airline.

Delayed each time on a round trip with no significant weather interference. Updates to flight times came after the fact. 30 min behind in boarding and board and phone still show an on time departure. Some mysterious extra 300 miles that came so surprising they had to fuel while we were already on board?

I ended up paying $70+ dollars to for a carryon because the website is confusing and misleading. I now realize I did not need to pay that. I request a refund. I will pay extra to other airlines and not fly Frontier again.

The crew was ghetto lol I felt like I was on an inner city field trip

Everything you need to know for your flight from Phoenix to Boulder

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