Southwest Airlines Co. (NYSE: LUV) and Singapore Airlines have launched an interline partnership that allows travelers to purchase single-ticket journeys connecting the carriers' networks. The partnership was announced during the International Air Transport Association Annual General Meeting in Brazil.

The agreement enables international travelers to connect between Singapore Airlines' flights and Southwest's domestic network at three shared gateway airports: Los Angeles, Seattle/Tacoma, and San Francisco. Singapore Airlines operates service to more than 130 destinations across 35 countries and territories from its Singapore Changi Airport hub.

Travelers can access nearly 120 airports in Southwest's network through these connections. Tickets are available through Singapore Airlines, travel agents, and travel websites.

"Singapore Airlines becomes the eighth carrier in our partnership portfolio," said Andrew Watterson, Southwest Airlines Chief Operating Officer. The airline now maintains eight active partnerships with overseas carriers connecting travel to destinations across Asia, Europe, the Middle East, and Africa.

Southwest has introduced assigned seating, optional extra legroom, and enhanced boarding procedures in 2026. The carrier has also initiated service at five new airports this year, including St. Thomas in the U.S. Virgin Islands, Sint Maarten, Santa Rosa/Sonoma County California, Knoxville Tennessee, and Anchorage.

Singapore Airlines Group, which includes Singapore Airlines and Scoot, operates flights between Singapore and the three U.S. airports served by Southwest. The SIA Group traces its history to 1947 with Malayan Airways, later becoming Singapore Airlines in 1972.