Welcome to Allegiant Air Group. Headquartered in Las Vegas, Nevada, Allegiant Air Group serves destinations across North America through an integrated network focused on leisure, connectivity, and operational efficiency. Following the merger with Sun Country Airlines, the group continues to strengthen its presence through unified operations, expanded services, and a shared commitment to safe and reliable travel. IATA: G4 ICAO: AAY Callsign: ALLEGIANT “Together We Fly.”