What terminal is United Airlines at SAN is a common query for travelers flying with United Airlines from San Diego International Airport (SAN). The answer to What terminal is United Airlines at SAN is that United Airlines operates out of Terminal 2 at SAN. This terminal handles all check-in, security, and boarding for United Airlines flights. The What terminal is United Airlines at SAN question is important for passengers to know in order to navigate the airport efficiently, as Terminal 2 offers a variety of amenities such as dining, shopping, and lounge options to ensure a comfortable pre-flight experience.