Joao Vianna (born November 15, 1966 in Trabajara, Brazil) was signed as a free agent by the Dallas Mavericks on October 3, 1991.
Vianna had played for Brazil in the 1988 Olympic games before being signed by the Mavs prior to the 1991-1992 season. He appeared in only one game for Dallas going 1-2 from the field and finishing with 2 points and 2 assists. With his Maverick career (not to mention his NBA career) lasting a grand total of one game, he joins a select group that includes Chucky Brown, Monti Davis, Adrian Caldwell, Randell Jackson, Mark Wade and Rodrick Rhodes as players who only had only one brief, shining moment in a Mavs uniform.
The 6'9 forward returned to international competition that included a successful career overseas and two more appearances in the Olympics with his native Brazil in 1992 and 1996.