Find flights
Airlines

$977+ Cheap flights to Boulder

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 20/5. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
30 May — 6 Jun1
1 adult
1 adult, Economy, 0 bags

Flights to Boulder in 2026

Enter your travel dates to find the best prices.

Cheapest flights to Boulder
Explore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 30 April 2026.

Mon 18/513:15
SYD
-
DEN
2 stops27h 23m
Multiple Airlines
Tue 19/507:20
DEN
-
SYD
2 stops36h 30m
Multiple Airlines
Deal found 29/4$1,336
Wed 13/513:15
SYD
-
DEN
3 stops34h 53m
Multiple Airlines
Sat 16/506:00
DEN
-
SYD
3 stops48h 10m
Multiple Airlines
Deal found 29/4$1,410
Wed 27/517:50
SYD
-
DEN
1 stop18h 16m
Multiple Airlines
Wed 3/614:00
DEN
-
SYD
1 stop25h 30m
Multiple Airlines
Deal found 29/4$1,486
Wed 20/517:50
SYD
-
DEN
1 stop32h 14m
Multiple Airlines
Wed 27/507:20
DEN
-
SYD
1 stop32h 10m
Multiple Airlines
Deal found 28/4$1,532
Tue 9/617:50
SYD
-
DEN
1 stop32h 12m
Multiple Airlines
Tue 16/607:25
DEN
-
SYD
1 stop32h 05m
Multiple Airlines
Deal found 25/4$1,576
Sun 2/814:10
SYD
-
DEN
2 stops26h 26m
Multiple Airlines
Fri 28/807:00
DEN
-
SYD
2 stops36h 50m
Multiple Airlines
Deal found 26/4$1,597
Fri 5/617:50
SYD
-
DEN
1 stop22h 48m
Multiple Airlines
Sun 28/607:00
DEN
-
SYD
1 stop32h 05m
Multiple Airlines
Deal found 26/4$1,701

Find flight deals to Boulder

Find the latest flights to Boulder in 2026, with up-to-date prices and availability. In the last 7 days, Cheapflights users made a total of 647,157 searches and data was last updated on 30 April 2026.

Return from

$1,336

One-way from

$977

Popular in

January

Cheapest in

November

Average price

$1,680
18/5-19/5
  • 18/5-19/5
  • 4 total stops
  • 63h 53m total
  • Sydney to Denver
Search Deals
20/5
  • 20/5
  • 1 total stop
  • 32h 14m total
  • Sydney to Boulder
Search Deals
Highest demand for flights based on searches. 9% potential increase in price ($172 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($37 potential savings vs. average return price).
Search Deals
Average for return flights in April 2026
Search Deals

Cheapflights Fare Finder

 
Locate flights to Boulder that fit your budget, with regularly updated fares and availability. In the last 7 days, Cheapflights users made a total of 647,157 searches and data was last updated on 30 April 2026.
Use the filters below to find and compare flights to Boulder that are best for you.

Fly from

Route

Depart

Return

Price

Cheapest return flight

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 9/6

17:50-10:02

1 stop32h 12m

Denver Intl

Tue 16/6

07:25-07:30

1 stop32h 05m

$1,576

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

13:15-23:59

2 stops26h 44m

Denver Intl

Sat 22/8

18:26-11:50

2 stops25h 24m

$1,986

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 11/5

13:15-20:03

2 stops22h 48m

Denver Intl

Sat 7/11

12:55-12:35

2 stops29h 40m

$1,987

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Wed 13/5

13:15-19:28

2 stops22h 13m

Denver Intl

Sun 8/11

16:45-12:35

2 stops25h 50m

$1,995

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Fri 22/5

20:45-19:11

2 stops38h 26m

Denver Intl

Wed 10/6

16:36-18:50

2 stops34h 14m

$2,113
Fastest return journey

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 17/9

09:15-18:10

1 stop24h 55m

Denver Intl

Fri 2/10

19:15-06:50

1 stop19h 35m

$2,421

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Sat 19/9

09:15-22:58

1 stop29h 43m

Denver Intl

Sun 4/10

12:59-07:50

1 stop25h 51m

$2,432

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

09:15-23:30

2 stops30h 15m

Denver Intl

Sat 22/8

06:30-06:50

1 stop32h 20m

$2,437
Cheapest one-way

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Fri 15/5

20:45-09:22

2 stops28h 37m

$1,108

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Sat 25/7

13:15-19:41

2 stops22h 26m

$1,160

Flights are sorted by cheapest return flights first.

Deals found on 29/4

Showing 1-10 of 14 resultsSorted by cheapest first
1
2

Best time to book a flight to Boulder

Have a flexible travel schedule? Discover the best time to fly to Boulder with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight to Boulder

How long is the flight to Boulder?

On average, a flight from Sydney to Boulder takes 22 hours 13 minutes. Flights to Boulder from other popular cities in Australia will vary in length. Below are a few examples of popular routes and their flight times.

What are the most popular airlines that fly to Boulder?

The most popular airlines flying from Sydney to Boulder are Air Canada, Qantas Airways and United Airlines.

Air Canada
Air Canada
From $1,199
Qantas Airways
Qantas Airways
From $680
United Airlines
United Airlines
From $1,351
Air New Zealand
Air New Zealand
From $1,205

What are the cheapest airlines that fly to Boulder?

The cheapest airlines flying from Sydney to Boulder are Qantas Airways, Air Canada and Air New Zealand.

Rainfall in Boulder by month

Plan your trip to Boulder by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Boulder ranges from 13.0 - 58.0 mm per month. May is typically the wettest month, when rainfall can reach 58.0 mm. January is typically the driest time to visit Boulder when rainfall is around 13.0 mm.

Temperature in Boulder by month

Plan your trip to Boulder by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Boulder, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -1.0 C).

Reviews of airlines servicing Boulder

Get insights into the airlines that provide service to Boulder. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Boulder. Reviews last updated 30 April 2026.
See what other customers who have flown with Air New Zealand,Qantas Airways, andUnited Airlines to the United States have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding
Air New Zealand
8.0
Very Good
638 reviews
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding
Qantas Airways
7.5
Good
1,028 reviews
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding
United Airlines
7.4
Good
9,677 reviews
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding
American Airlines
7.1
Good
11,682 reviews
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding
Air Canada
7.1
Good
10,982 reviews
Air New Zealand
8.0
Very Good
638 reviews
Check prices

Entertainment

7.4

Overall

8.0

Boarding

8.2

Food

7.4

Comfort

7.9

Crew

8.5

Reviews

1 / 20
6.0
Good

Anonymous,Mar 2026

SIN - AKL

We were stuck on tarmac for an hour after boarding

FAQs about flying to Boulder

  • Can I find cheaper flights to Boulder if I am willing to have stopovers?

    Yes, flights with stopovers are often cheaper than direct flights. Keep an eye out for flight deals to Boulder on Cheapflights that require 1 or 2 stops for potential cost savings.

  • What is the best airline to fly to Boulder?

    Based on reviews from Cheapflights users, Qantas Airways is rated the highest out of the airlines that fly to Boulder.

  • How much is a return flight to Boulder?

    A return flight to Boulder will typically cost around $452, however they can be found for as little as $278.

  • Where does the fastest flight to Boulder depart from?

    For those looking to save time traveling to Boulder, Sydney Kingsford Smith offers the quickest one-way flight (22 hours 13 minutes).

  • Does Denver Intl have car hire?

    Yes. Those touching down at Denver Intl can take advantage of the car hire services offered upon their arrival.

  • Are there hotels close to Denver Intl?

    Yes. Denver Intl has hotels nearby for those requiring accommodations. The Westin Denver International Airport is the closest property to Denver Intl (0.0 km away from Denver Intl).

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Search flights to Boulder by cabin class

Find flights to Boulder, based on your preferred cabin class, be it economy, premium economy, business, or first class.
First Class flights to Boulder
Business Class flights to Boulder
Prem Economy Class flights to Boulder
Economy Class flights to Boulder

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights to Boulder?

When you search for this flight to Boulder, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the best flight for you.

Why should you use Cheapflights to find cheap flight tickets to Boulder?

Cheapflights helps you find that perfect flight to Boulder by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights to Boulder with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights to Boulder flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights to Boulder become cheaper?

Not ready to book yet? You can track prices for flights to Boulder on Cheapflights with our Price Alerts feature and get notified when better prices are available.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.