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$1,146+ 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 25/7. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
17 Jul — 24 Jul1
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 17 June 2026.

Wed 26/806:05
SYD
-
DEN
3 stops37h 53m
Multiple Airlines
Wed 2/907:25
DEN
-
SYD
2 stops36h 25m
Multiple Airlines
Deal found 16/6$1,148
Sat 1/809:10
SYD
-
DEN
1 stop31h 19m
Multiple Airlines
Sat 15/807:00
DEN
-
SYD
1 stop32h 05m
Multiple Airlines
Deal found 12/6$1,494
Tue 3/1111:20
SYD
-
DEN
2 stops23h 18m
Air Canada
Wed 18/1119:00
DEN
-
SYD
1 stop20h 35m
Air Canada
Deal found 11/6$1,496
Tue 3/1111:20
SYD
-
DEN
2 stops23h 18m
Multiple Airlines
Wed 18/1115:55
DEN
-
SYD
2 stops23h 40m
Multiple Airlines
Deal found 11/6$1,504
Wed 4/1111:20
SYD
-
DEN
1 stop18h 48m
Air Canada
Thu 19/1119:00
DEN
-
SYD
1 stop20h 35m
Air Canada
Deal found 12/6$1,507
Mon 16/1111:20
SYD
-
DEN
1 stop19h 09m
Air Canada
Tue 24/1119:00
DEN
-
SYD
1 stop20h 35m
Air Canada
Deal found 14/6$1,513
Mon 16/1111:20
SYD
-
DEN
2 stops22h 54m
Multiple Airlines
Tue 24/1111:49
DEN
-
SYD
1 stop27h 46m
Multiple Airlines
Deal found 14/6$1,520

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 17 June 2026.

Return from

$1,148

One-way from

$1,146

Popular in

June

Cheapest in

November

Average price

$2,275
26/8-2/9
  • 26/8-2/9
  • 5 total stops
  • 74h 18m total
  • Sydney to Denver
Search Deals
Fiji Airways
  • Fiji Airways
  • 25/7
  • 2 total stops
  • 22h 26m total
  • Sydney to Boulder
Search Deals
Highest demand for flights based on searches. 18% potential increase in price ($386 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($50 potential savings vs. average return price).
Search Deals
Average for return flights in June 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 17 June 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

Sat 7/11

11:20-17:18

1 stop23h 58m

Denver Intl

Sun 22/11

13:25-09:35

2 stops50h 10m

$1,599
Fastest return journey

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 27/7

17:50-00:29

1 stop22h 39m

Denver Intl

Sun 9/8

15:20-07:30

1 stop24h 10m

$1,777

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 27/7

12:00-15:30

1 stop19h 30m

Denver Intl

Sun 9/8

07:00-07:05

1 stop32h 05m

$1,786

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

09:55-20:09

2 stops26h 14m

Denver Intl

Sat 22/8

17:45-10:40

2 stops24h 55m

$1,832

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 25/8

17:50-10:02

1 stop32h 12m

Denver Intl

Thu 3/9

12:32-07:30

1 stop26h 58m

$1,832

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

12:00-17:37

1 stop21h 37m

Denver Intl

Sat 22/8

07:00-07:05

1 stop32h 05m

$1,847

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 27/7

10:20-08:20

2 stops38h 00m

Denver Intl

Sun 9/8

06:00-06:55

1 stop32h 55m

$1,910

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 17/8

10:20-08:21

2 stops38h 01m

Denver Intl

Sat 22/8

07:45-06:55

1 stop31h 10m

$1,956
Cheapest one-way
Fastest single journey

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Sat 25/7

13:15-19:41

2 stops22h 26m

$1,146

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Sat 25/7

09:20-17:13

1 stop23h 53m

$1,240

Flights are sorted by cheapest return flights first.

Deals found on 12/6

Showing 1-10 of 11 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 21 hours 35 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 $1,230
United Airlines
United Airlines
From $552
Qantas Airways
Qantas Airways
From $1,186
Air New Zealand
Air New Zealand
From $1,218

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 17 June 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
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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
645 reviews
Air New Zealand
8.0
Very Good
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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
1,047 reviews
Air New Zealand
8.0
Very Good
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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
9,844 reviews
Air New Zealand
8.0
Very Good
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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
11,668 reviews
Air New Zealand
8.0
Very Good
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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
11,200 reviews
Air New Zealand
8.0
Very Good
645 reviews
Check prices

Boarding

8.2

Entertainment

7.4

Food

7.4

Overall

8.0

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, 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 $758, however they can be found for as little as $81.

  • 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 (21 hours 35 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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