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$548+ 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 15/10. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
28 Aug — 4 Sep1
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 29 July 2026.

Mon 3/809:20
SYD
-
DEN
1 stop30h 32m
Air Canada
Mon 17/818:05
DEN
-
SYD
2 stops45h 15m
Air Canada
Deal found 28/7$1,128
Wed 9/909:20
SYD
-
DEN
1 stop29h 48m
Air Canada
Wed 16/909:10
DEN
-
SYD
1 stop30h 10m
Air Canada
Deal found 29/7$1,142
Thu 6/809:20
SYD
-
DEN
1 stop30h 32m
Air Canada
Thu 13/816:00
DEN
-
SYD
2 stops23h 20m
Air Canada
Deal found 27/7$1,148
Wed 9/909:20
SYD
-
DEN
1 stop23h 38m
Air Canada
Mon 14/918:05
DEN
-
SYD
2 stops45h 15m
Air Canada
Deal found 28/7$1,190
Wed 28/1010:20
SYD
-
DEN
2 stops23h 16m
Air Canada
Sun 1/1115:53
DEN
-
SYD
2 stops30h 47m
Air Canada
Deal found 28/7$1,237
Thu 5/1114:00
SYD
-
DEN
2 stops28h 25m
Multiple Airlines
Sat 21/1110:25
DEN
-
SYD
2 stops32h 10m
Multiple Airlines
Deal found 27/7$1,260
Thu 6/809:20
SYD
-
DEN
1 stop30h 32m
Air Canada
Wed 12/819:16
DEN
-
SYD
2 stops44h 04m
Air Canada
Deal found 28/7$1,272

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 29 July 2026.

Return from

$1,142

One-way from

$548

Popular in

July

Cheapest in

March

Average price

$2,477
Air Canada
  • Air Canada
  • 9/9-16/9
  • 2 total stops
  • 59h 58m total
  • Sydney to Denver
Search Deals
15/10
  • 15/10
  • 2 total stops
  • 27h 10m total
  • Sydney to Boulder
Search Deals
Highest demand for flights based on searches. 16% potential increase in price ($366 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($62 potential savings vs. average return price).
Search Deals
Average for return flights in July 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 29 July 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

Mon 3/8

09:20-23:52

1 stop30h 32m

Denver Intl

Mon 17/8

09:10-07:20

1 stop30h 10m

$1,131

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 6/8

13:15-03:50

3 stops30h 35m

Denver Intl

Wed 12/8

09:15-22:25

3 stops45h 10m

$1,389

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Wed 9/9

17:50-15:05

1 stop37h 15m

Denver Intl

Mon 14/9

13:10-07:30

1 stop26h 20m

$1,403

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Fri 21/8

13:15-10:03

2 stops36h 48m

Denver Intl

Fri 28/8

22:39-07:30

1 stop40h 51m

$1,618

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 24/9

09:20-23:08

1 stop29h 48m

Denver Intl

Sun 11/10

18:05-08:20

2 stops45h 15m

$1,641
Fastest return journey

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 4/8

11:55-22:15

2 stops26h 20m

Denver Intl

Sat 8/8

18:05-08:45

2 stops22h 40m

$1,689

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Wed 9/9

09:20-16:10

2 stops22h 50m

Denver Intl

Wed 16/9

07:45-07:20

3 stops31h 35m

$1,786

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

09:20-23:52

1 stop30h 32m

Denver Intl

Sat 22/8

09:10-07:20

1 stop30h 10m

$1,805

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

09:55-22:08

2 stops28h 13m

Denver Intl

Sat 22/8

17:45-08:45

2 stops23h 00m

$1,888
Cheapest one-way

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 15/10

14:15-00:25

2 stops27h 10m

$548

Flights are sorted by cheapest return flights first.

Deals found on 24/7

Showing 1-10 of 16 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 18 hours 49 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 $1,219
United Airlines
United Airlines
From $525
Qantas Airways
Qantas Airways
From $1,201
Air New Zealand
Air New Zealand
From $1,146

What are the cheapest airlines that fly to Boulder?

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

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 29 July 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
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.
Air New Zealand
8.0
Very Good
656 reviews
Air New Zealand
8.0
Very Good
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.
Qantas Airways
7.5
Good
1,073 reviews
Air New Zealand
8.0
Very Good
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.
United Airlines
7.4
Good
10,052 reviews
Air New Zealand
8.0
Very Good
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.
American Airlines
7.1
Good
11,839 reviews
Air New Zealand
8.0
Very Good
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.
Air Canada
7.1
Good
11,404 reviews
Air New Zealand
8.0
Very Good
656 reviews
Check prices

Entertainment

7.4

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.5

Boarding

8.2

Reviews

1 / 20
2.0
Mediocre

Viren,June 2026

MEL - LAX

Flight got delayed and made us take a transit visa which was not a told before hand.

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, American Airlines 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 $479, however they can be found for as little as $113.

  • 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 (18 hours 49 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

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