Juan M. Alvarez (born August 9, 1973) is an American former professional baseball player who played four seasons for the Anaheim Angels, Texas Rangers, and Florida Marlins of Major League Baseball The California Angels signed Alvarez as an amateur free agent on July 25, 1995.

Alvarez spent nearly the entire 2003 season in the Marlins' minor league system, appearing in only 9 games, before being released on October 15, 2003.

Alvarez was signed as a free agent by the New York Yankees on February 10, 2004, but didn't play a game with the team, being released on April 3.

Alvarez shares the major league baseball record with Ed Olwine for most games pitched without a win, at 80.

In 2006, Alvarez was the pitching coach for the Everett AquaSox of the Northwest League in the Seattle Mariners' organization.