$86 Cheap United flights Phoenix (PHX) to San Diego (SAN)

Use the "Price (lowest to highest)" filter on Expedia to look for cheap United Airlines round-trip flights from $166 from PHX to SAN. Affordable one-way fares from $86 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.

Look for cheap United Airlines flights from Sky Harbor Intl. Airport (PHX) to San Diego Intl. Airport (SAN) one to three months ahead of your day of departure. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. Regardless of fare type and itinerary, the best day to book a domestic flight is usually Sunday and the most expensive is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**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.

Browse United Airlines's earliest flights from PHX to SAN by using our "Morning" and "Early Morning" filters. Not only will you arrive sooner, early departures also have a 20% less chance of being canceled.**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.

With a rewarding loyalty program, United Airlines is a top pick for many travelers heading from PHX to SAN. Plus, as a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.