Marcelo Ríos, Chilean tennis player
Marcelo Andrés Ríos Mayorga (American Spanish: [maɾˈselo ˈri.os]; born 26 December 1975) is a Chilean former world No. 1 tennis player. Nicknamed El Chino ("The Chinese") and El zurdo de Vitacura ("The Lefty from Vitacura"), he became the first Latin American player to reach the top position on the Association of Tennis Professionals (ATP) singles rankings in March 1998, holding the spot for six weeks. He also held the top ranking in juniors.

Ríos was the first player to win all three clay-court Masters Series tournaments (Monte Carlo, Rome, and Hamburg) since the format began in 1990. He was also the third man in history (after Michael Chang and Pete Sampras) to complete the Sunshine Double (winning Indian Wells and Miami Masters in one year), which he achieved in 1998. Despite winning those five Masters titles, Ríos is also the only man in the Open Era to have been world No. 1 without ever winning a Grand Slam singles tournament. His best major result was as runner-up at the 1998 Australian Open, losing to Petr Korda in straight sets.

Ríos retired early from professional tennis in July 2004, after being overtaken by a back injury. He played his last ATP Tour level tournament while only 27 years old at the 2003 French Open.