$125+ Cheap flights from San Francisco (SFO) 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 7/8. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — DEN
Jul 20 — Jul 271
Round-trip
1 adult, Economy
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Find cheap flights from San Francisco to Boulder with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from San Francisco to Boulder are usually found in October or September, booked 71 days in advance, depart on a Wednesday or Saturday and return on a Friday
Cheap flight deals from San Francisco to Boulder
Cheapest
Best
Last-minute
One-way
Cheapest flights from San Francisco to BoulderExplore the most affordable flight options available from San Francisco to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 20, 2026.
Explore the most affordable flight options available from San Francisco to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 20, 2026.
This Frontier deal was found by Cheapflights users on 6/16. 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.
Wed 8/510:07 pm
SFO
- DEN
1 stop9h 58m
Frontier
Sat 8/1510:29 pm
DEN
- SFO
Nonstop2h 49m
Frontier
Deal found 6/16![Frontier logo]()
$217
This Frontier deal was found by Cheapflights users on 6/16. 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.
Thu 7/99:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Tue 7/149:49 am
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/16![Frontier logo]()
$218
This Kiwi.com deal was found by Cheapflights users on 6/15. 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.
Tue 7/288:23 pm
SFO
- DEN
1 stop12h 40m
Frontier
Thu 7/3010:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/15![Frontier logo]()
$219
This Super.com deal was found by Cheapflights users on 6/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/106:04 pm
SFO
- DEN
Nonstop2h 45m
Frontier
Thu 8/133:00 pm
DEN
- SFO
Nonstop2h 47m
Frontier
Deal found 6/18![Frontier logo]()
$220
This Cheapflightsfares deal was found by Cheapflights users on 6/15. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/66:04 pm
SFO
- DEN
Nonstop2h 45m
Frontier
Mon 8/103:22 pm
DEN
- SFO
Nonstop2h 47m
Frontier
Deal found 6/15![Frontier logo]()
$222
This Super.com deal was found by Cheapflights users on 6/17. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/116:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Mon 7/1310:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/17![Frontier logo]()
$223
This Cheapflightsfares deal was found by Cheapflights users on 6/19. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/116:30 am
SFO
- DEN
1 stop16h 45m
Frontier
Sun 9/1310:29 pm
DEN
- SFO
Nonstop2h 46m
Frontier
Deal found 6/19![Frontier logo]()
$225
This Frontier deal was found by Cheapflights users on 6/16. 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.
Sat 8/16:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Mon 8/103:22 pm
DEN
- SFO
Nonstop2h 47m
Frontier
Deal found 6/16![Frontier logo]()
$226
This Frontier deal was found by Cheapflights users on 6/19. 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.
Sun 10/112:07 pm
SFO
- DEN
Nonstop2h 40m
Frontier
Thu 10/156:30 am
DEN
- SFO
1 stop5h 17m
Frontier
Deal found 6/19![Frontier logo]()
$227
This Frontier deal was found by Cheapflights users on 6/18. 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.
Thu 7/99:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Thu 7/166:58 pm
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 6/18![Frontier logo]()
$228
Best flights from San Francisco to BoulderDiscover carefully curated flight deals from San Francisco to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 20, 2026.
Discover carefully curated flight deals from San Francisco to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 20, 2026.
This Alaska Airlines deal was found by Cheapflights users on 6/15. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/115:16 pm
SFO
- DEN
1 stop5h 28m
Alaska Airlines
Sat 9/121:43 pm
DEN
- SFO
1 stop6h 23m
Alaska Airlines
Deal found 6/15![Alaska Airlines logo]()
$308
This Southwest deal was found by Cheapflights users on 6/15. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/237:40 am
SFO
- DEN
1 stop4h 20m
Southwest
Mon 9/283:10 pm
DEN
- SFO
2 stops6h 20m
Southwest
Deal found 6/15![Southwest logo]()
$326
This Delta deal was found by Cheapflights users on 6/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/259:30 am
SFO
- DEN
1 stop7h 48m
Delta
Thu 8/2712:54 pm
DEN
- SFO
2 stops11h 56m
Delta
Deal found 6/19![Delta logo]()
$406
This United Airlines deal was found by Cheapflights users on 6/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/36:56 pm
SFO
- DEN
Nonstop2h 48m
United Airlines
Thu 8/66:00 am
DEN
- SFO
Nonstop2h 35m
United Airlines
Deal found 6/18![United Airlines logo]()
$409
This Southwest deal was found by Cheapflights users on 6/15. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/2710:15 am
SFO
- DEN
1 stop5h 45m
Southwest
Mon 8/313:10 pm
DEN
- SFO
2 stops6h 20m
Southwest
Deal found 6/15![Southwest logo]()
$338
This Southwest deal was found by Cheapflights users on 6/15. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/3012:30 pm
SFO
- DEN
2 stops6h 30m
Southwest
Mon 8/36:15 am
DEN
- SFO
2 stops6h 05m
Southwest
Deal found 6/15![Southwest logo]()
$347
This Southwest deal was found by Cheapflights users on 6/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/185:00 am
SFO
- DEN
2 stops7h 50m
Southwest
Sat 7/256:35 am
DEN
- SFO
2 stops9h 35m
Southwest
Deal found 6/19![Southwest logo]()
$360
This Delta deal was found by Cheapflights users on 6/18. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/236:00 am
SFO
- DEN
2 stops9h 53m
Delta
Sat 9/261:00 pm
DEN
- SFO
2 stops11h 36m
Delta
Deal found 6/18![Delta logo]()
$494
This Southwest deal was found by Cheapflights users on 6/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/812:10 pm
SFO
- DEN
2 stops7h 50m
Southwest
Thu 7/911:00 am
DEN
- SFO
1 stop4h 25m
Southwest
Deal found 6/19![Southwest logo]()
$402
This Southwest deal was found by Cheapflights users on 6/17. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/135:10 am
SFO
- DEN
Nonstop2h 30m
Southwest
Thu 7/168:05 pm
DEN
- SFO
1 stop5h 50m
Southwest
Deal found 6/17![Southwest logo]()
$407
This Southwest deal was found by Cheapflights users on 6/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/3012:30 pm
SFO
- DEN
2 stops6h 30m
Southwest
Sun 8/28:00 am
DEN
- SFO
2 stops6h 35m
Southwest
Deal found 6/18![Southwest logo]()
$457
This Southwest deal was found by Cheapflights users on 6/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/245:00 am
SFO
- DEN
2 stops6h 25m
Southwest
Sun 7/268:00 am
DEN
- SFO
2 stops6h 35m
Southwest
Deal found 6/19![Southwest logo]()
$479
Last-minute flights from San Francisco to BoulderDiscover last-minute flight deals from San Francisco to Boulder. Data last updated June 20, 2026 and is based on user searches.
Discover last-minute flight deals from San Francisco to Boulder. Data last updated June 20, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 6/18. 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.
Wed 7/16:00 am
SFO
- DEN
Nonstop2h 49m
Frontier
Wed 7/1510:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/18![Frontier logo]()
$220
This Kiwi.com deal was found by Cheapflights users on 6/17. 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.
Wed 7/810:23 pm
SFO
- DEN
1 stop10h 40m
Frontier
Wed 8/510:29 pm
DEN
- SFO
1 stop12h 56m
Frontier
Deal found 6/17![Frontier logo]()
$225
This Frontier deal was found by Cheapflights users on 6/16. 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.
Thu 7/99:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Tue 7/149:49 am
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/16![Frontier logo]()
$218
This Kiwi.com deal was found by Cheapflights users on 6/16. 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.
Thu 7/99:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Sat 7/1810:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/16![Frontier logo]()
$224
This Frontier deal was found by Cheapflights users on 6/18. 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.
Thu 7/99:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Thu 7/166:58 pm
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 6/18![Frontier logo]()
$228
This Super.com deal was found by Cheapflights users on 6/17. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/116:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Mon 7/1310:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/17![Frontier logo]()
$223
This Kiwi.com deal was found by Cheapflights users on 6/18. 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 7/136:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Thu 7/1610:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/18![Frontier logo]()
$221
This Kiwi.com deal was found by Cheapflights users on 6/18. 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 7/166:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Thu 7/1610:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/18![Frontier logo]()
$222
This Kiwi.com deal was found by Cheapflights users on 6/16. 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.
Thu 7/236:00 am
SFO
- DEN
Nonstop2h 46m
Frontier
Sat 7/2510:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/16![Frontier logo]()
$227
This Cheapflightsfares deal was found by Cheapflights users on 6/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/259:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Sat 8/110:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/18![Frontier logo]()
$226
This Kiwi.com deal was found by Cheapflights users on 6/15. 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.
Tue 7/288:23 pm
SFO
- DEN
1 stop12h 40m
Frontier
Thu 7/3010:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 6/15![Frontier logo]()
$219
This Cheapflightsfares deal was found by Cheapflights users on 6/16. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/309:39 pm
SFO
- DEN
Nonstop2h 50m
Frontier
Tue 8/410:00 am
DEN
- SFO
1 stop6h 25m
Frontier
Deal found 6/16![Frontier logo]()
$217
One-way flights from San Francisco to BoulderSearch for one-way flight options from San Francisco to Boulder. Find affordable one-way fares based on user searches. Data last updated June 20, 2026.
Search for one-way flight options from San Francisco to Boulder. Find affordable one-way fares based on user searches. Data last updated June 20, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/17. 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.
Wed 7/811:20 am
SFO
- DEN
1 stop9h 21m
Frontier
Deal found 6/17![Frontier logo]()
$125
This Kiwi.com deal was found by Cheapflights users on 6/17. 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 7/1411:15 am
SFO
- DEN
2 stops9h 26m
Frontier
Deal found 6/17![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 6/18. 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.
Wed 7/2210:23 pm
SFO
- DEN
1 stop14h 18m
Frontier
Deal found 6/18![Frontier logo]()
$127
This Kiwi.com deal was found by Cheapflights users on 6/16. 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.
Wed 7/1511:20 am
SFO
- DEN
1 stop5h 40m
Frontier
Deal found 6/16![Frontier logo]()
$128
This Kiwi.com deal was found by Cheapflights users on 6/17. 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 7/910:23 pm
SFO
- DEN
1 stop10h 40m
Frontier
Deal found 6/17![Frontier logo]()
$130
This Kiwi.com deal was found by Cheapflights users on 6/18. 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.
Wed 7/2911:15 am
SFO
- DEN
2 stops9h 26m
Frontier
Deal found 6/18![Frontier logo]()
$132
This Kiwi.com deal was found by Cheapflights users on 6/19. 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 8/145:11 pm
SFO
- DEN
1 stop13h 32m
Frontier
Deal found 6/19![Frontier logo]()
$134
This Frontier deal was found by Cheapflights users on 6/17. 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 9/117:17 pm
SFO
- DEN
Nonstop2h 42m
Frontier
Deal found 6/17![Frontier logo]()
$135
This Southwest deal was found by Cheapflights users on 6/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/46:35 am
SFO
- DEN
Nonstop2h 25m
Southwest
Deal found 6/19![Southwest logo]()
$136
Find flight deals from San Francisco to Boulder
Keep the following information in mind while searching for San Francisco to Boulder flight deals. Data was last updated June 20, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $217 (Frontier) |
One-way from | $125 (Kiwi.com) |
Popular in | June |
Cheapest in | October |
Average price | $345 |
Cheapflights Fare Finder
Customize your flight search to find flights from San Francisco 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 June 20, 2026.
Use the filters below to find and compare flights from San Francisco to Boulder that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Fri 9/11
5:16 pm-11:44 pm
1 stop5h 28m
Denver Intl
Sat 9/12
1:43 pm-7:06 pm
1 stop6h 23m
$308
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Wed 9/23
7:40 am-1:00 pm
1 stop4h 20m
Denver Intl
Mon 9/28
3:10 pm-8:30 pm
2 stops6h 20m
$326
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Thu 8/27
10:15 am-5:00 pm
1 stop5h 45m
Denver Intl
Mon 8/31
3:10 pm-8:30 pm
2 stops6h 20m
$338
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Thu 7/30
12:30 pm-8:00 pm
2 stops6h 30m
Denver Intl
Mon 8/3
6:15 am-11:20 am
2 stops6h 05m
$347
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Sat 7/18
5:00 am-1:50 pm
2 stops7h 50m
Denver Intl
Sat 7/25
6:35 am-3:10 pm
2 stops9h 35m
$360
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Wed 7/8
12:10 pm-9:00 pm
2 stops7h 50m
Denver Intl
Thu 7/9
11:00 am-2:25 pm
1 stop4h 25m
$402
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Tue 8/25
9:30 am-6:18 pm
1 stop7h 48m
Denver Intl
Thu 8/27
12:54 pm-11:50 pm
2 stops11h 56m
$406
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Mon 7/13
5:10 am-8:40 am
Nonstop2h 30m
Denver Intl
Thu 7/16
8:05 pm-12:55 am
1 stop5h 50m
$407
Quickest round-trip
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Mon 8/3
6:56 pm-10:44 pm
Nonstop2h 48m
Denver Intl
Thu 8/6
6:00 am-7:35 am
Nonstop2h 35m
$409
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Thu 7/30
12:30 pm-8:00 pm
2 stops6h 30m
Denver Intl
Sun 8/2
8:00 am-1:35 pm
2 stops6h 35m
$457
Showing 1-10 of 24 resultsSorted by cheapest first
Best time to book a flight from San Francisco to Boulder
Have a flexible travel schedule? Discover the best time to fly to Boulder from San Francisco with our price prediction graph.
SFO-DEN
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 San Francisco to Boulder
SFO-BD9
SFO-DEN
What is the cheapest time of day to fly from SFO to BD9?
Find hourly flight availability from San Francisco 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 June 20, 2026.
It’s typically best to fly out from San Francisco to Boulder in the evening. Doing so could potentially save you 27% on the flight price compared to flying at noon, which is usually more expensive.
Weekly flight availability from San Francisco to Boulder
Explore weekly flight availability from San Francisco 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 June 20, 2026.
The most flights from SFO to BD9 are scheduled on a Friday (61 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (41 on average).
How much does it cost to fly round-trip from San Francisco to Boulder?
What is the cheapest day to fly from San Francisco to Boulder?
Use this chart to determine the cheapest time to fly round-trip from San Francisco to Boulder. Price data was last updated on June 13, 2026.
Travelers seeking maximum savings on their San Francisco to Boulder flight should consider departing on Friday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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 June 20, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andUnited Airlines from San Francisco to Boulder to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
7.9
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Related info for your journey
Find useful and relevant information for your journey from San Francisco to Boulder. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for San Francisco to Boulder
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Boulder by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from San Francisco to Boulder by cabin class
Find flights from San Francisco to Boulder, based on your preferred cabin class, be it economy, premium economy, business, or first class.
San Francisco and Boulder flights
Browse other San Francisco and Boulder flight options. Last updated on June 20, 2026.
Other flights from San Francisco
Browse through other flights departing from San Francisco. Flights are based on user searches made on Cheapflights and were last updated on June 20, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
San Francisco to Boulder flights
Consider these flights traveling from San Francisco to Boulder.
Top 5 airlines flying from San Francisco to Boulder
Discover the top 5 airlines that operate flights from San Francisco 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 June 20, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$83 | Average$228 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$157 | Average$392 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$184 | Average$372 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$196 | Average$371 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$226 | Average$342 | FlexibilityNo cancel fee | On-time62% |