Stefano Mezzadri (born 26 May 1967) is a Swiss former professional tennis player.
Mezzadri appeared in his only Grand Prix circuit singles main draw at Geneva in 1987, with the tournament won by his older brother Claudio, a Davis Cup representative for Switzerland. As a doubles player he was a semi-finalist at Geneva in 1990 and won one ATP Challenger title. He played in qualifiers at the 1987 Wimbledon Championships.