$94+ 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 6/13. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — DEN
Jun 1 — Jun 81
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 36 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 May 2, 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 May 2, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 4/27. 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 5/295:25 pm
SFO
- DEN
1 stop6h 06m
Frontier
Tue 6/210:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/27![Frontier logo]()
$163
This Super.com deal was found by Cheapflights users on 4/27. 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.
Tue 5/266:00 am
SFO
- DEN
Nonstop2h 52m
Frontier
Tue 6/210:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/27![Frontier logo]()
$166
This Frontier deal was found by Cheapflights users on 4/28. 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.
Mon 5/116:00 am
SFO
- DEN
Nonstop2h 52m
Frontier
Thu 5/1410:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/28![Frontier logo]()
$168
This Frontier deal was found by Cheapflights users on 4/28. 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 6/45:25 pm
SFO
- DEN
1 stop6h 06m
Frontier
Mon 6/86:05 am
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 4/28![Frontier logo]()
$169
This Frontier deal was found by Cheapflights users on 4/29. 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 5/308:56 am
SFO
- DEN
Nonstop2h 54m
Frontier
Sun 6/79:03 am
DEN
- SFO
1 stop8h 27m
Frontier
Deal found 4/29![Frontier logo]()
$170
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 5/1312:52 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Wed 5/2010:29 pm
DEN
- SFO
1 stop13h 09m
Frontier
Deal found 4/29![Frontier logo]()
$171
This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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.
Mon 6/299:43 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Sat 7/410:29 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/29![Frontier logo]()
$172
This Frontier deal was found by Cheapflights users on 4/29. 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 6/209:43 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Sat 6/2710:29 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/29![Frontier logo]()
$174
This Kiwi.com deal was found by Cheapflights users on 4/30. 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 6/28:41 pm
SFO
- DEN
1 stop5h 44m
Frontier
Thu 6/117:00 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/30![Frontier logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 6/35:26 pm
SFO
- DEN
1 stop5h 43m
Frontier
Mon 6/86:05 am
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 4/29![Frontier logo]()
$176
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 6/305:16 pm
SFO
- DEN
1 stop21h 01m
Frontier
Tue 7/1410:51 am
DEN
- SFO
1 stop8h 17m
Frontier
Deal found 4/29![Frontier logo]()
$177
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 May 2, 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 May 2, 2026.
This United Airlines deal was found by Cheapflights users on 5/1. 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.
Thu 5/285:00 am
SFO
- DEN
Nonstop2h 35m
United Airlines
Mon 6/15:20 am
DEN
- SFO
Nonstop2h 38m
United Airlines
Deal found 5/1![United Airlines logo]()
$317
This Alaska Airlines deal was found by Cheapflights users on 4/28. 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 10/236:00 am
SFO
- DEN
1 stop4h 34m
Alaska Airlines
Tue 10/278:20 am
DEN
- SFO
1 stop7h 53m
Alaska Airlines
Deal found 4/28![Alaska Airlines logo]()
$337
This Southwest deal was found by Cheapflights users on 4/29. 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 9/295:50 am
SFO
- DEN
2 stops7h 10m
Southwest
Sat 10/35:40 am
DEN
- SFO
2 stops6h 50m
Southwest
Deal found 4/29![Southwest logo]()
$347
This Delta deal was found by Cheapflights users on 4/27. 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.
Sun 7/55:25 pm
SFO
- DEN
1 stop4h 16m
Delta
Tue 7/145:40 am
DEN
- SFO
1 stop7h 21m
Delta
Deal found 4/27![Delta logo]()
$397
This Southwest deal was found by Cheapflights users on 4/30. 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 7/155:50 am
SFO
- DEN
2 stops6h 45m
Southwest
Mon 7/206:15 am
DEN
- SFO
2 stops6h 05m
Southwest
Deal found 4/30![Southwest logo]()
$347
This Alaska Airlines deal was found by Cheapflights users on 5/1. 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.
Sat 5/303:00 pm
SFO
- DEN
2 stops7h 59m
Alaska Airlines
Thu 6/46:40 am
DEN
- SFO
1 stop6h 13m
Alaska Airlines
Deal found 5/1![Alaska Airlines logo]()
$360
This United Airlines deal was found by Cheapflights users on 4/30. 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.
Wed 8/126:28 pm
SFO
- DEN
Nonstop2h 43m
United Airlines
Sun 8/167:40 am
DEN
- SFO
Nonstop2h 41m
United Airlines
Deal found 4/30![United Airlines logo]()
$377
This Southwest deal was found by Cheapflights users on 5/1. 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 7/15:50 am
SFO
- DEN
2 stops6h 45m
Southwest
Tue 7/78:15 am
DEN
- SFO
2 stops7h 00m
Southwest
Deal found 5/1![Southwest logo]()
$366
This Alaska Airlines deal was found by Cheapflights users on 5/1. 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.
Sat 5/303:00 pm
SFO
- DEN
2 stops7h 59m
Alaska Airlines
Fri 6/56:40 am
DEN
- SFO
1 stop5h 09m
Alaska Airlines
Deal found 5/1![Alaska Airlines logo]()
$413
This Southwest deal was found by Cheapflights users on 4/28. 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 5/283:40 pm
SFO
- DEN
2 stops7h 05m
Southwest
Sat 5/3010:10 am
DEN
- SFO
2 stops8h 15m
Southwest
Deal found 4/28![Southwest logo]()
$417
This Southwest deal was found by Cheapflights users on 4/29. 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 5/297:25 am
SFO
- DEN
2 stops6h 30m
Southwest
Mon 6/15:10 pm
DEN
- SFO
2 stops6h 15m
Southwest
Deal found 4/29![Southwest logo]()
$417
Last-minute flights from San Francisco to BoulderDiscover last-minute flight deals from San Francisco to Boulder. Data last updated May 2, 2026 and is based on user searches.
Discover last-minute flight deals from San Francisco to Boulder. Data last updated May 2, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 4/28. 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.
Mon 5/116:00 am
SFO
- DEN
Nonstop2h 52m
Frontier
Thu 5/1410:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/28![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 5/1312:52 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Wed 5/2010:29 pm
DEN
- SFO
1 stop13h 09m
Frontier
Deal found 4/29![Frontier logo]()
$171
This Super.com deal was found by Cheapflights users on 4/27. 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.
Tue 5/266:00 am
SFO
- DEN
Nonstop2h 52m
Frontier
Tue 6/210:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/27![Frontier logo]()
$166
This Cheapflightsfares deal was found by Cheapflights users on 4/27. 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 5/295:25 pm
SFO
- DEN
1 stop6h 06m
Frontier
Tue 6/210:29 pm
DEN
- SFO
Nonstop2h 54m
Frontier
Deal found 4/27![Frontier logo]()
$163
This Frontier deal was found by Cheapflights users on 4/29. 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 5/308:56 am
SFO
- DEN
Nonstop2h 54m
Frontier
Sun 6/79:03 am
DEN
- SFO
1 stop8h 27m
Frontier
Deal found 4/29![Frontier logo]()
$170
This Kiwi.com deal was found by Cheapflights users on 4/30. 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 6/28:41 pm
SFO
- DEN
1 stop5h 44m
Frontier
Thu 6/117:00 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/30![Frontier logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 6/35:26 pm
SFO
- DEN
1 stop5h 43m
Frontier
Mon 6/86:05 am
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 4/29![Frontier logo]()
$176
This Frontier deal was found by Cheapflights users on 4/28. 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 6/45:25 pm
SFO
- DEN
1 stop6h 06m
Frontier
Mon 6/86:05 am
DEN
- SFO
Nonstop2h 56m
Frontier
Deal found 4/28![Frontier logo]()
$169
This Frontier deal was found by Cheapflights users on 4/29. 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 6/209:43 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Sat 6/2710:29 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/29![Frontier logo]()
$174
This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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.
Mon 6/299:43 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Sat 7/410:29 pm
DEN
- SFO
Nonstop2h 58m
Frontier
Deal found 4/29![Frontier logo]()
$172
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 6/305:16 pm
SFO
- DEN
1 stop21h 01m
Frontier
Tue 7/1410:51 am
DEN
- SFO
1 stop8h 17m
Frontier
Deal found 4/29![Frontier logo]()
$177
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 May 2, 2026.
Search for one-way flight options from San Francisco to Boulder. Find affordable one-way fares based on user searches. Data last updated May 2, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 4/30. 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 6/139:43 pm
SFO
- DEN
Nonstop2h 51m
Frontier
Deal found 4/30![Frontier logo]()
$94
This Super.com deal was found by Cheapflights users on 4/29. 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.
Fri 5/159:19 am
SFO
- DEN
1 stop27h 53m
Frontier
Deal found 4/29![Frontier logo]()
$95
This Mytrip deal was found by Cheapflights users on 4/29. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/139:26 pm
SFO
- DEN
1 stop11h 35m
Frontier
Deal found 4/29![Frontier logo]()
$96
This Kiwi.com deal was found by Cheapflights users on 5/1. 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 6/3012:32 am
SFO
- DEN
1 stop16h 05m
Frontier
Deal found 5/1![Frontier logo]()
$98
This Kiwi.com deal was found by Cheapflights users on 5/1. 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 6/2210:27 pm
SFO
- DEN
1 stop10h 39m
Frontier
Deal found 5/1![Frontier logo]()
$99
This Super.com deal was found by Cheapflights users on 4/29. 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.
Wed 6/1710:27 pm
SFO
- DEN
1 stop10h 39m
Frontier
Deal found 4/29![Frontier logo]()
$100
This Kiwi.com deal was found by Cheapflights users on 4/28. 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 6/1510:58 pm
SFO
- DEN
1 stop24h 40m
Frontier
Deal found 4/28![Frontier logo]()
$101
This Kiwi.com deal was found by Cheapflights users on 4/27. 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.
Sun 5/179:19 am
SFO
- DEN
1 stop27h 53m
Frontier
Deal found 4/27![Frontier logo]()
$103
This Kiwi.com deal was found by Cheapflights users on 4/28. 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 5/2110:01 pm
SFO
- DEN
1 stop11h 00m
Frontier
Deal found 4/28![Frontier logo]()
$104
This Trip.com deal was found by Cheapflights users on 5/2. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/1810:58 pm
SFO
- DEN
1 stop18h 06m
Frontier
Deal found 5/2![Frontier logo]()
$105
This Kiwi.com deal was found by Cheapflights users on 4/28. 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 6/911:13 am
SFO
- DEN
2 stops9h 29m
Frontier
Deal found 4/28![Frontier logo]()
$106
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 May 2, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $168 (Kiwi.com) |
One-way from | $94 (Cheapflightsfares) |
Popular in | March |
Cheapest in | October |
Average price | $261 |
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 May 2, 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
Quickest round-trip
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Thu 5/28
5:00 am-8:35 am
Nonstop2h 35m
Denver Intl
Mon 6/1
5:20 am-6:58 am
Nonstop2h 38m
$317
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Fri 10/23
6:00 am-11:34 am
1 stop4h 34m
Denver Intl
Tue 10/27
8:20 am-3:13 pm
1 stop7h 53m
$337
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Tue 9/29
5:50 am-2:00 pm
2 stops7h 10m
Denver Intl
Sat 10/3
5:40 am-11:30 am
2 stops6h 50m
$347
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Wed 7/15
5:50 am-1:35 pm
2 stops6h 45m
Denver Intl
Mon 7/20
6:15 am-11:20 am
2 stops6h 05m
$347
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Sat 5/30
3:00 pm-11:59 pm
2 stops7h 59m
Denver Intl
Thu 6/4
6:40 am-11:53 am
1 stop6h 13m
$360
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Wed 7/1
5:50 am-1:35 pm
2 stops6h 45m
Denver Intl
Tue 7/7
8:15 am-2:15 pm
2 stops7h 00m
$366
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Wed 8/12
6:28 pm-10:11 pm
Nonstop2h 43m
Denver Intl
Sun 8/16
7:40 am-9:21 am
Nonstop2h 41m
$377
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Sun 7/5
5:25 pm-10:41 pm
1 stop4h 16m
Denver Intl
Tue 7/14
5:40 am-12:01 pm
1 stop7h 21m
$397
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Sat 5/30
3:00 pm-11:59 pm
2 stops7h 59m
Denver Intl
Fri 6/5
6:40 am-10:49 am
1 stop5h 09m
$413
San FranciscoDenver
SFO - DEN
SFODEN
San Francisco
Thu 5/28
3:40 pm-11:45 pm
2 stops7h 05m
Denver Intl
Sat 5/30
10:10 am-5:25 pm
2 stops8h 15m
$417
Showing 1-10 of 23 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 May 2, 2026.
It’s typically best to fly out from San Francisco to Boulder in the evening. Doing so could potentially save you 32% on the flight price compared to flying at noon, which is usually more expensive.
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 April 25, 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.
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 May 2, 2026.
The most flights from SFO to BD9 are scheduled on a Saturday (56 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (42 on average).
How much does it cost to fly round-trip from San Francisco to Boulder?
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 May 2, 2026.
Peruse reviews from past customers who have flown with Southwest,United Airlines, andAllegiant Air 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.
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Boarding
8.1
Food
7.0
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
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
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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 May 2, 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 May 2, 2026.
Popular flight searches
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San Francisco to Boulder flights
Consider these flights traveling from San Francisco to Boulder.
Top 7 airlines flying from San Francisco to Boulder
Discover the top 7 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 May 2, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$80 | Average$212 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$87 | Average$96 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$157 | Average$381 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$175 | Average$314 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$176 | Average$508 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$178 | Average$358 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$226 | Average$337 | FlexibilityNo cancel fee | On-time62% |