Southwest Airlines will commence services to Aruba, and Montego Bay, Jamaica, from Atlanta, Baltimore and Orlando.
The routes mark the carrier’s first international destinations in 43 years of operation.
Later this year, Southwest expects to launch flights to the Bahamas and Mexico from other airports across the US.
Southwest executive Teresa Laraba said: “Obviously we’ve been waiting for 43 years to get to this point. It’s a pretty big deal. It’s such an opportunity for us to plant our name and flag in international waters, and we’ve never done it.”
Southwest has launched the services in a bid to undercut competitors on the routes which the airline believes are “over-fared”.