San Francisco International Airport (SFO) terminal guide

San Francisco, California KSFO #10 US airport by passengers

How SFO is laid out and how to move between buildings.

Terminals at SFO

Terminal 1 (Harvey Milk Terminal)

Recently rebuilt. Serves several domestic airlines; check your ticket or the airport website for your airline.

Terminal 2

Serves several domestic airlines; check your ticket or the airport website for your airline.

Terminal 3

United Airlines is the main user, along with some partner airlines.

International Terminal (Boarding Areas A and G)

Most international flights, including United's international departures from Boarding Area G. BART connects directly to this terminal.

Moving between terminals

AirTrain runs on two loops (Blue and Red) that connect all terminals, garages, the rental car center and the BART station. It is free. Inside security, you can walk between some of the terminals, but the International Terminal and the domestic terminals are separate for security purposes.

Reviewed October 8, 2026. Confirm details on the official airport website. Spotted a change?

Frequently asked questions

Which terminal is United at?

Terminal 3 for domestic, and the International Terminal (Boarding Area G) for most international flights.