$176 Cheap United flights San Juan (SJU) to San Diego (SAN)

Set the "Price (lowest to highest)" filter on Expedia to look for cheap United Airlines round-trip flights from $345 from SJU to SAN. Affordable one-way fares from $176 are available too.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Start your search for United Airlines flights from SJU to SAN about one month before you want to go. The most affordable time to book an international flight is generally 18 to 29 days ahead of your departure date when you can save 17% versus booking four to five months in advance. Regardless of itinerary and fare class, the best day of the week to book international airfare is usually Sunday. Friday can be the most expensive. Passengers booking on a Sunday can save 17% on average compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Filter your results by "Morning" and "Early Morning" to browse the earliest departures from SJU to SAN. Taking off early means you're 20% less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

Journey from SJU to SAN with United Airlines and look forward to a range of perks including a rewarding loyalty program. When you book through Expedia as a United Mileage Plus and One Key™ member, you could also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.