$1,222+ Cheap flights from San Francisco (SFO) to Ulsan (USN)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/24. Fares are subject to change and may not be available on all flights or dates of travel.
Find cheap flights from San Francisco to Ulsan 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
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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from San Francisco to Ulsan
Cheapest flights from San Francisco to UlsanExplore the most affordable flight options available from San Francisco to Ulsan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 15, 2025.
Explore the most affordable flight options available from San Francisco to Ulsan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 15, 2025.
This Trip.com deal was found by Cheapflights users on 12/15. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Korean Air deal was found by Cheapflights users on 12/15. 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 Korean Air is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Find flight deals from San Francisco to Ulsan
Discover tips and strategies to find the most affordable flight options for your journey from San Francisco (SFO) to Ulsan (USN). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated December 15, 2025.
Most accurate provider | Expedia 2 stars |
|---|---|
Most trusted provider | Expedia 3 stars |
Cheapflights Fare Finder
Use the filters below to find and compare flights from San Francisco to Ulsan that are best for you.
Fly from
Fly to
Route
Depart
Return
Price
San FranciscoUlsan
SFO - USN
SFOUSN
San Francisco
Wed 12/24
11:35 am-2:05 pm
2 stops33h 30m
Ulsan
Wed 1/21
2:25 pm-9:50 am
2 stops36h 25m
San FranciscoUlsan
SFO - USN
SFOUSN
San Francisco
Wed 12/24
11:40 am-8:50 am
1 stop28h 10m
Ulsan
Wed 1/21
8:20 pm-9:30 am
1 stop30h 10m
- Most accurate provider: When it comes to deals on San Francisco-Ulsan flights, users find the pricing of Expedia to be most consistent on Cheapflights vs. Expedia Users can find the same prices on San Francisco-Ulsan flight deals on Cheapflights vs. Expedia 90-95% of the time. Price accuracy is based on data collected from San Francisco-Ulsan flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on San Francisco-Ulsan flights, Cheapflights users trust Expedia the most. Expedia has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for San Francisco-Ulsan flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from San Francisco to Ulsan
Have a flexible travel schedule? Discover the best time to fly to Ulsan from San Francisco with our price prediction graph.
Cheapflights Insights
Everything you need to know about your flight from San Francisco to Ulsan
What is the cheapest month to book a flight from San Francisco to Ulsan?
Currently, April is the cheapest month in which you can book a flight from San Francisco to Ulsan (average of $786). Flying from San Francisco to Ulsan in December is currently the most expensive (average of $1,593). 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 SFO to USN?
One of the essential ways to save on airfare from San Francisco to Ulsan is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 61% on airfare.
What is the cheapest day to fly from San Francisco to Ulsan?
Travelers seeking maximum savings on their San Francisco to Ulsan flight should consider departing on Monday at noon when fares are most often at their lowest. Sunday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.
How often are flights from San Francisco to Ulsan delayed?
About 14% of weekly flights between San Francisco and Ulsan have experienced delays in the past year, with the average delay time being 157 minutes.
What is the most punctual flight time for San Francisco to Ulsan flights?
Historically, flights departing at night are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Saturday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on San Francisco to Ulsan flights?
Over the last year, United Airlines have had the lowest number of delays on this route, with just 6% of flights being delayed.