United Airlines and Expedia have round trip airfares travelling from San Francisco (SFO) to Seoul South Korea (ICN) for $643, nonstop. These are basic economy fares on both airlines and include a personal item, a carry-on bag and 1 free checked bag. There is no seat selection and no change. If you are travelling with children, you will be seated together as per UA’s policy.

One way outbound is available for $349 if you want to fly into Seoul for a few days, then head to another destination in Asia on a regional carrier, returning to San Fran from there.