Los 40 (The 40, stylized as LOS40 and formerly Los 40 Principales, Spanish: Los-Cuarenta) is a Top 40 musical radio network and radio station brand in many Spanish-speaking countries from Prisa Radio. The station has its origins as a music show at Radio Madrid, today Cadena SER in 1966, where the 40 Principales chart was born, then evolved into a standalone radio station in 1979. LOS40 is the number one music station in most of the regions it serves.
Some stations under this brand name are owned and operated or are licensed by Grupo PRISA to use the brand. Some LOS40 stations are operated by a local broadcasting company and affiliated with the company that holds a license to use the brand from Grupo PRISA. Each LOS40 network typically broadcasts its own national feed from its respective country.
Most LOS40 networks generally air Spanish and English contemporary hit music that mostly includes American, Latin American, Pan-European, and British singers and bands. Most stations emphasize Latin Top 40 music; however, Mexico and Panama stations feature more European and English-language music whilst Chile and Costa Rica stations play more reggaeton and bachata. It has a high-rotation playlist consisting mainly of tracks from its private chart. The main music genres that can be heard are pop, pop-rock, and some dance music from the '90s, '00s, and the present day.