If you are traveling with Allegiant Air and wondering what terminal is Allegiant in Las Vegas, you will find that all Allegiant flights operate out of Terminal 1 at Harry Reid International Airport, formerly known as McCarran International Airport. This terminal is specifically designed to handle domestic carriers, making it convenient for passengers flying with Allegiant. Located on the south side of the airport, Terminal 1 features Concourse A and Concourse B, where Allegiant Air typically operates its departures and arrivals. Travelers can easily access ticketing counters, baggage claim, and security checkpoints within Terminal 1, ensuring a smooth airport experience.