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Find cheap flights to Boulder from $911

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 26/8. 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
Mon 8/7
Mon 15/7

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Low season

February

High season

June

Cheapest flight

$911
Best time to beat the crowds (20% less expensive on average)
Most popular time to fly (7% more expensive on average)
Flight from Sydney to Denver

FAQs - booking Boulder flights

  • 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 hire a car or take a taxi.

  • What airports are near Boulder?

    The closest airport is Denver Intl (DEN) (53.76 km). Another nearby airport is Colorado Springs (COS) (142.97 km) KAYAK recommends you fly to Denver Intl.

  • How far is Denver from central Denver?

    There are 30 km between Denver city centre and Denver.

  • What is the name of Denver’s airport?

    All flights to Denver land at Denver. The airport code is DEN,and it can also be referred to 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.

See more FAQs

Top tips for finding cheap flights to Boulder

  • There is no major airport in Boulder. It is instead served by Denver Intl Airport.
  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest Boulder flight deals.

Top 5 airlines flying to Boulder

Need help choosing which airline to fly with from Australia 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.
8.2
Air New ZealandOverall score based on 604 reviews
8.4Boarding
8.7Crew
7.9Entertainment
7.6Food
8.1Comfort
Airline reviews

Can you please process refund. Mum died and dad went to Pakistan to bury her after cancelling flight.

2.0 MediocreAnonymous, May 2024AKL - YVR
Read more about Air New Zealand reviews

Can you please process refund. Mum died and dad went to Pakistan to bury her after cancelling flight.

Overall excellent but the Captain kept the seat belt sign on for far too long, especially at the beginning and end of the flight. It was 2 hours after take-off before the crew were able to start the service (on an 11 hour night flight, reducing our sleeping time) and the seat belt sign on went on during breakfast (90 mins before landing) and was not turned off again until we landed. This made for an uncomfortable journey of trying to limit fluid intake because it was unclear when the toilets would be available for use.

The staff and crew on board were excellent. Business class however, was very weird. I thought we would have individual pods, but the way it was set up was unexpected. Not very private and If you wanted to lay down, you had to have an entire bed made up for you by the crew, rather than how Delta one works where you could just lie down whenever you feel like it. It was a 16 hour flight. I chose not to have my bed made, and that turned out to be a good idea because everybody who had their bed made had to wait for the crew to roll up their mattresses. So strange!

Food was not good. We asked for Muslim food and it was weird tasteless type of boiled veges.

Crew were pleasant, happy to be there and were a joy to be around. Entire operation was professional, well thought out and ran like a Swiss clock.

Couldn’t request a vegan meal somehow but I noticed other people getting them

They announced food service but then never came around. We also couldn’t land so kept trying to get to runway and then had to come up and go around happened like 3 times and cause the child next to me to start throwing up

Good food and entertainment options. Great Staff that were all welcoming and caregiving.

The recline on the seat in front of me came back so that I was staring at the top of the man’s head in front of me the whole trip. He refused to bring his seat back up twice every time he was instructed to do so and only relented when he had a tray of good in front of him. And then right back in my lap!!! Horrible man!! I complained to the staff multiple times, but no one would address the issue. Otherwise, it would have been a perfect flight.

Flight was canceled due to technical issue shortly before the check-in counters opened. Passengers were rebooked on a flight three days later. Request to be accommodated on Air Tahiti Nui could not be processed. Customer service sorted out the refund after calling and being put on hold for almost an hour.

The seats are so uncomfortable. The food doesn't exist unless you pay. Disappointed

This time is good . Don’t cancel flight with out early notice .

Very good experience, considering the short flight the meals were served promptly after takeoff.

X class seats in row 3 with the new configuration are very poor in fact I feel 3B and 3E should no longer be considered as X class seat as there is no forward seat pocket available to these seats and greatly reduced leg room due the intrusion of the business class armrests/table module

It was pretty good. Everyone friendly. Like all airlines, the draconian limitations on baggage and weight and not giving even a free soda kind of drags down the experience a bit.

Last 10 minutes boarding they canceled the flight and didn’t organise anything

Estheticly the plane looks great, although the seats are way too upright. If the seats were just slightly more reclined then the comfort level would increase tenfold. I had the stiffest neck after just a short flight due to this. A nap was almost out of the question.

Cabin crew were very professional and welcoming. They certainly appeared to have lifted their game. Congratulations

I know not directly a Virgin "thing" but I hold Virgin responsible for their subcontractors. Had to wait 45 minutes waiting for baggage at PER before the belt conveyor even started. This is unacceptable and hopefully Virgin engages with whoever to pull their fingers out. I realise PER staff are generally slow at the best of times but this was ridiculous. Maybe more seating for those waiting, a cafe in the baggage area for a light meal while we wait or at the very least a troop of dancing girls to entertain the punters while they stare at the conveyor belt start light almost willing it to fire up.

Very poor. Flight was cancelled due to captain exceeding hours. Told to fend for ourselves for 12 hours until a new flight could be done. This meant overnight accommodation in Hobart. Next plane was delayed and no food onboard. No apologies from Virgin. Extremely disappointing.

The seats are too close together and are smaller than they used to be. Makes for a cramped experience.

Great. Airhostess was amazing. Dinner a little spicy! Could have had a mention beforehand about that though

The international flight from Sydney to Dallas had great food. I have travelled a lot over the years and this has been the most memorable in my experience so far.

Initial flight was cancelled so moved to an alternative flight. As a result, stuck in a middle seat. Flight then place in holding pattern prior to landing resulting in a very late trip home.

There was nothing I didn’t like, prices a little lower would help

BA Airbus A380 BC upstairs had 2 3 2 layout. The seat was comfy but access for those in middle or window seats had to climb over others fest to get to ailse when seats in bed mode. The layout was not nearly as private as other layouts. The staff was amazing as well as the food. Most airline food is average but this was restaurant quality.

Following a marathon flight riddled by delays and changes from Santiago, Chile, my flight to Melbourne from Sydney was on schedule but I was transferred to the next flight. The reason by ticketing and the floor manager was I missed the entry to flight by one minute! That's right, the emphasised that if I was 1 minute earlier I would be on the flight. I asked what was the point them emphasising 1minute overdue and how that helped me or the situation. They didn't care at all. Replying that if it was one minute earlier they would've done something and smirking delivering the information. Australian's do call Australia home, Qantas calls Australian's suckers.

1) crackly headphone jack 2) one of the emergency seats recline. Usually second row does. But in this case neither did 3) food was scrambled eggs or fruit. 4) fruit should not be the option to eggs 5)miserable unpleasant crew not a smile. Thought that was a virgin thing

Qantas are unable to service and unfit for purpose, they cannot transport Australians on time to overseas destinations. On top of the inflated ticketing, the Sydney flight to Santiago was impacted because the plane was delayed arriving and then further bungling by Qantas admitting the ground new ground crew in charge of cleaning were not trained. The impact on passengers with connecting flights was tremendous and long ques of frustrated passengers waiting for rescheduling. **Qantas has become the Australian Spirit of disappointment**

The staff we fantastic and seemed to work very well with each other

Not worth the price of premium class ticket paid, felt more like steerage.

I have to wait for plane in Denver for three hours. I don’t receive my luggage in Denver. I come back home without the luggage and I wait till next day to see my luggage again. Not really good experience with United airlines. I’m sorry to say that.

The Wi-Fi was unavailable on this flight for some reason.

This was a Lufthansa flight, not United. The CSA at the counter, Ashley, was not only incompetent, but quite rude. Me and two other PAX waited over 7 minutes standing in front of her and another CSA and they ignored us. We joked that we must have accidently taken invisibility pills. She could have at least said "I'll be with you in a moment, I'm currently....". I could go on about how rude she and the other CSAs were (whispering, not communicating with me, blaming the situation on others, etc.). She would not work for me. Then, she gave me literally the worst seat on the plane. the worst. My seat kept getting bumped (rammed twice by the crew with their carts and about every 5 minutes by someone using the bathroom), listening to the bathroom all night, crowded seat, etc.

We ended up with seats in the very back. So they did not recline. Have no idea why, we reserved and checked in very early. The isles were very narrow and the seats had very little leg room. But they did give us water, and a snack.

I paid $380 for my one-way ticket from California to Minnesota. The fair did not include online check-in. I received instructions from their app to check in at a kiosk. At the kiosk, the boarding pass would not print until an actual person came to verify that I had a personal item and not a carry-on item, On the plane, the person next to me was drunk and allowed to continue to order alcohol. United is garbage I’d rather fly spirit.

The plane was dirty and the in seat air wasn't blowing as planes usually do.

Generally good but there wasn’t any staff available when my luggage didn’t appear at baggage claim in Fresno. It took about half an hour to locate a staff member to open up the room where it was being kept.

T hey did a great job. Flight was on time .

Positive: Entertainment via phone on the short was great and my first time. Good food and wine and head phones for free. Negative: Seat hardly reclined on the long flight. Breakfast was an egg with a bun. No egg choices and rather have something sweet like bun/jam and Youghurt.

My husbands flight last night Vancouver/Sydney was 90 minutes late in leaving. My flight tonight Vancouver/Seattle was also late in departing.

My mother, 80years old, had arranged for wheelchair assist to and from the aircraft cabin and in the airport but, no one showed up for her to de-plane. Apart from Air Canada having a reputation of being late for every leg of its flight so nothing was new this time so this time they did worse by not assisting seniors. I guess our whole family is done with this airline

Flights delayed over 4 hours with no compensation. No agents at counters to assist with re-booking.

Seating for almost 3 hours in the plan before aircraft takeoff. Very exhausted .

The bathroom did not have hand soap. That is unacceptable.

The only problem I encountered was they changed the gate on me while I was sitting down but no one notified me, they had sent me an email and by coincidence I checked it and found out that they had changed my boarding terminal. No one notified me and when I had asked the lady she told me yes this is the spot while they had already changed to another gate/terminal

I was seated next to someone who was, to be polite, not a small person. I had to press myself against the wall as I had no personal space. Aside from that the crew was wonderful and they got me home safely, which is the most important part of my journey. I am very appreciative to your air crews for the job they have, which isn't easy, and appreciative of the fact that they are professional and courteous. The employees I encountered on my journey, with the few exceptions I mentioned in a previous review, are a credit to Air Canada.

Air Canada had a lot of delays on our flight going back to Seattle. So much inconvenience for a long trip.

Moderate size plane, not completely full, easy boarding, some rows with just 2 seats so a couple can have a row to themselves

The Carry-on luggage that approved by TSA and all other airlines,- always an issue with Air Canada. This is inappropriate as my carry on suitcase meets the requirements however it always asked to check in on AC flight on the gate. Yes I have it for free, but it takes extra time to pick up on the carousel. Apparently it fit the overhead space, so why AC has this issue all the time?

Book Cheap Boulder Plane Tickets

Recent return flight deals

26/7Fri
2 stops
28h 15mSYD-DEN
17/8Sat
2 stops
38h 34mDEN-SYD
$1,222
12/8Mon
1 stopAmerican Airlines
18h 12mSYD-DEN
21/8Wed
1 stopAmerican Airlines
27h 05mDEN-SYD
$1,443
26/7Fri
1 stopQantas Airways
24h 07mSYD-DEN
17/8Sat
2 stopsQantas Airways
24h 23mDEN-SYD
$1,547
20/11Wed
1 stopQantas Airways
19h 06mSYD-DEN
4/12Wed
1 stopQantas Airways
26h 09mDEN-SYD
$1,579
20/11Wed
2 stopsAir Canada
23h 20mSYD-DEN
4/12Wed
2 stopsAir Canada
27h 55mDEN-SYD
$1,587
16/10Wed
1 stopAir Canada
25h 52mSYD-DEN
23/10Wed
1 stopAir Canada
29h 35mDEN-SYD
$1,731
19/6Wed
1 stopUnited Airlines
22h 10mBNE-DEN
30/6Sun
1 stopUnited Airlines
27h 15mDEN-BNE
$2,584
19/6Wed
2 stopsUnited Airlines
22h 09mBNE-DEN
1/7Mon
2 stopsUnited Airlines
22h 40mDEN-BNE
$2,591
11/8Sun
2 stopsVirgin Australia
33h 23mMEL-DEN
8/9Sun
1 stopVirgin Australia
24h 20mDEN-MEL
$8,785
11/8Sun
2 stopsVirgin Australia
31h 53mMEL-DEN
8/9Sun
2 stopsVirgin Australia
22h 17mDEN-MEL
$8,822

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1 stopAmerican Airlines
24h 52mSYD-DEN
$911
26/8Mon
2 stopsAmerican Airlines
24h 27mSYD-DEN
$919
25/10Fri
1 stopQantas Airways
23h 24mSYD-DEN
$1,579
16/9Mon
1 stopUnited Airlines
27h 20mMEL-DEN
$1,682
13/6Thu
1 stopUnited Airlines
27h 55mSYD-DEN
$1,733
14/6Fri
1 stopAir Canada
23h 18mSYD-DEN
$1,734
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23h 09mSYD-DEN
$1,828
19/6Wed
1 stopVirgin Australia
25h 06mBNE-DEN
$1,882
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22h 28mCBR-DEN
$3,955

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12/6Wed
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18h 33mSYD-DEN
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23h 15mDEN-SYD
$5,413
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22h 19mSYD-DEN
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