XEX-FM (101.7 FM) is a commercial radio station in Mexico City.

Broadcasting from a tower atop the World Trade Center Mexico City, XEX-FM airs a contemporary hit radio format and is the flagship station of the Mexican Los 40 network.

It carried a adult contemporary music sound as "Stereo 102", but most of its history has been marked by frequent format changes.

It later was "Yo 102", a contemporary hit radio format giving the station some ratings success.

The two companies launched the "Los 40 Principales" brand in Mexico, which was popular in Spain and other Latin American countries.