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$66+ Cheap flights from Portland (PDX) to Boulder, CO

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 2/21. Fares are subject to change and may not be available on all flights or dates of travel.
PDX — DEN
Nov 15 — Nov 221
Sat 11/15
Sat 11/22
1 adult, Economy
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Cheapflights Tip: The best prices from Portland to Boulder are usually found in August or January, booked 30 days in advance, depart on a Friday or Saturday and return on a Saturday

Find flight deals from Portland to Boulder

Cheapest flights from Portland to Boulder
Explore the most affordable flight options available from Portland to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 16, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/143:26 pmPDX - DEN
Nonstop2h 41mFrontier
Mon 11/1710:05 amDEN - PDX
Nonstop2h 51mFrontier
Deal found 10/15$95
This Kiwi.com deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/76:35 pmPDX - DEN
1 stop26h 14mFrontier
Mon 11/1010:05 amDEN - PDX
Nonstop2h 51mFrontier
Deal found 10/15$96
This Frontier deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/73:26 pmPDX - DEN
Nonstop2h 41mFrontier
Sat 11/1510:05 amDEN - PDX
Nonstop2h 51mFrontier
Deal found 10/15$97
This Kiwi.com deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1312:52 pmPDX - DEN
Nonstop2h 43mFrontier
Sun 11/1610:29 pmDEN - PDX
1 stop21h 02mFrontier
Deal found 10/15$99
This Frontier deal was found by Cheapflights users on 10/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/3110:02 pmPDX - DEN
1 stop12h 19mFrontier
Sun 11/210:05 amDEN - PDX
Nonstop2h 51mFrontier
Deal found 10/16$102
This Orbitz deal was found by Cheapflights users on 10/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/263:59 pmPDX - DEN
Nonstop2h 33mMultiple Airlines
Wed 12/311:41 amDEN - PDX
Nonstop3h 00mMultiple Airlines
Deal found 10/16$103
This Kiwi.com deal was found by Cheapflights users on 10/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/41:26 pmPDX - DEN
Nonstop2h 47mFrontier
Thu 11/610:00 amDEN - PDX
1 stop26h 08mFrontier
Deal found 10/14$105
This Kiwi.com deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/173:26 pmPDX - DEN
Nonstop2h 41mMultiple Airlines
Wed 11/1911:31 amDEN - PDX
Nonstop2h 53mMultiple Airlines
Deal found 10/15$108
This Kiwi.com deal was found by Cheapflights users on 10/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/111:26 pmPDX - DEN
Nonstop2h 47mMultiple Airlines
Wed 11/1211:31 amDEN - PDX
Nonstop2h 53mMultiple Airlines
Deal found 10/16$109
This Priceline deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/73:26 pmPDX - DEN
Nonstop2h 41mFrontier
Sun 11/99:48 amDEN - PDX
1 stop5h 43mFrontier
Deal found 10/15$110

Cheap flight deals from Portland to Boulder

Keep the following information in mind while searching for Portland to Boulder flight deals. Data was last updated October 16, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$95
(Kiwi.com)

One-way from

$66
(Netflights)

Popular in

March

Cheapest in

August

Average price

$209
Provider with most accurate pricing for Portland-Denver Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Portland-Denver Intl flights.
Search Deals
From Portland to Boulder
Search Deals
One-way flight from Portland to Boulder
Search Deals
Highest demand for flights based on searches. 0% potential increase in price ($2 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($3 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland to Boulder that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 16, 2025.
Use the filters below to find and compare flights from Portland to Boulder that are best for you.

Fly from

Portland

Fly to

Boulder

Route

Depart

Return

Price

PortlandDenver

PDX - DEN

PDXDEN

Portland

Thu 11/13

12:52 pm-4:35 pm

Nonstop2h 43m

Denver Intl

Sun 11/16

9:48 am-2:31 pm

1 stop5h 43m

$110

PortlandDenver

PDX - DEN

PDXDEN

Portland

Sat 11/8

4:02 pm-7:35 pm

Nonstop2h 33m

Denver Intl

Tue 11/11

7:46 am-9:38 am

Nonstop2h 52m

$137

PortlandDenver

PDX - DEN

PDXDEN

Portland

Thu 11/6

7:10 pm-10:43 pm

Nonstop2h 33m

Denver Intl

Tue 11/11

6:00 am-10:53 am

1 stop5h 53m

$153

PortlandDenver

PDX - DEN

PDXDEN

Portland

Sat 11/15

5:30 pm-11:57 pm

1 stop5h 27m

Denver Intl

Tue 11/18

7:00 am-12:38 pm

1 stop6h 38m

$156

PortlandDenver

PDX - DEN

PDXDEN

Portland

Sat 11/8

5:30 pm-11:57 pm

1 stop5h 27m

Denver Intl

Sat 11/15

7:00 am-1:50 pm

1 stop7h 50m

$156

PortlandDenver

PDX - DEN

PDXDEN

Portland

Tue 3/10

5:45 pm-11:22 pm

1 stop4h 37m

Denver Intl

Wed 3/11

6:15 am-10:34 am

1 stop5h 19m

$157

PortlandDenver

PDX - DEN

PDXDEN

Portland

Fri 1/30

6:20 am-9:45 am

Nonstop2h 25m

Denver Intl

Mon 2/2

8:40 am-10:35 am

Nonstop2h 55m

$157

PortlandDenver

PDX - DEN

PDXDEN

Portland

Sat 11/8

5:25 pm-11:14 pm

1 stop4h 49m

Denver Intl

Tue 11/11

6:05 am-10:55 am

1 stop5h 50m

$157

PortlandDenver

PDX - DEN

PDXDEN

Portland

Mon 12/8

1:34 pm-11:59 pm

1 stop9h 25m

Denver Intl

Wed 12/31

7:20 am-9:18 am

Nonstop2h 58m

$157

PortlandDenver

PDX - DEN

PDXDEN

Portland

Thu 1/8

7:21 am-10:53 am

Nonstop2h 32m

Denver Intl

Sat 1/10

5:09 pm-10:46 pm

1 stop6h 37m

$157

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/16

Showing 1-10 of 21 results
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Best time to book a flight from Portland to Boulder

Have a flexible travel schedule? Discover the best time to fly to Boulder from Portland with our price prediction graph.
Estimated round-trip 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 from Portland to Boulder

How far ahead should I book a flight from Portland to Boulder?

Use this chart to determine the optimal time to book a round-trip flight from Portland to Boulder. Price data was last updated on October 10, 2025.

To ensure you get the cheapest price possible for a flight from Portland to Boulder, you should look to book at least 30 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Portland to Boulder?

Currently, February is the cheapest month in which you can book a flight from Portland to Boulder (average of $39). Flying from Portland to Boulder in July is currently the most expensive (average of $98). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from PDX to BD9?

Find hourly flight availability from Portland to Boulder. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 16, 2025.

Unlike at noon, when flights are generally more expensive, you can save up to 46% on flights from Portland to Boulder by exploring options for tickets in the morning.

What is the cheapest day to fly from Portland to Boulder?

Use this chart to determine the cheapest time to fly round-trip from Portland to Boulder. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Portland to Boulder flight should consider departing on Friday mornings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Portland to Boulder

Explore weekly flight availability from Portland to Boulder. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated October 16, 2025.

The most flights from PDX to BD9 are scheduled on a Thursday (19 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (5 on average).

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 October 16, 2025.
Read through reviews of airlines operating flights from Portland to Boulder, such as Alaska Airlines, Southwest, and Hawaiian Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.
Alaska Airlines
8.0
Very good
11,103 reviews
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.
Southwest
8.0
Very good
4,241 reviews
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.
Hawaiian Airlines
7.8
Good
2,781 reviews
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.
United Airlines
7.4
Good
8,982 reviews
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.
Frontier
5.8
Fair
3,137 reviews
Alaska Airlines
8.0
Very good
11,103 reviews

Entertainment

7.0

Food

7.1

Boarding

8.1

Crew

8.5

Comfort

7.8

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

BOS - HNL

The flight was awesome but a little long. I would prefer a flight with a layover. The amount of space available was minimal and a little uncomfortable for that long of a flight.

Related info for your journey

Find useful and relevant information for your journey from Portland to Boulder. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Portland to Boulder?

    Most people fly from Portland (PDX) if they book a flight from Portland to Boulder. On average, Portland has 13 outbound flights to Boulder per day from 6 airlines. Portland is conveniently located just 6.0 mi from Portland’s city center.

  • How popular is this Portland to Boulder flight route?

    Within the past month, 215 users have taken a look at flights from Portland to Boulder.

  • How long is the flight from Portland to Boulder?

    Airlines like Frontier, United Airlines, and Alaska Airlines fly from Portland to Boulder in about 2h 33m. The time it takes to get you to your destination can typically vary by up to 2h 54m. Portland and Boulder are separated by a distance of 989 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the most reliable airlines from Portland to Boulder?

    Consider SWISS (87%), United Airlines (86%) or Lufthansa (85%) when booking your flight. These represent the most reliable airlines when flying from Portland to Boulder.

  • What are the cheapest flights from Portland to Boulder?

    Looking for the cheapest flight from Portland to Boulder? While on average our users pay $754, our data indicates the cheapest price to be $79. The most popular route (Portland - Denver Intl), is priced around $107.

  • Can I find deals for flights from Portland to Boulder that include hotel bookings?

    Yes. In addition to deals on Portland to Boulder flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Portland to Boulder?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Boulder.

  • Can I find deals for business class flights from Portland to Boulder?

    Yes. Cheapflights offers flight deals from Portland to Boulder by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Portland to Boulder?

    Currently, February is the cheapest month in which you can book a flight from Portland to Boulder (average of $39). Flying from Portland to Boulder in July is currently the most expensive (average of $98). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Alternative routes for Portland to Boulder

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from Portland to Boulder

Discover the top 6 airlines that operate flights from Portland to Boulder. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 16, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$59Average$147FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$98Average$234FlexibilityNo cancel feeOn-time85%
SouthwestCheapest$157Average$309FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$160Average$379FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$170Average$266FlexibilityNo cancel feeOn-time75%
DeltaCheapest$196Average$266FlexibilityNo cancel feeOn-timeN/A

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