This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)(Learn how and when to remove this template message)
|Born||March 23, 1976|
Rio de Janeiro, Brazil
|Rank||5th Degree Black Belt in Brazilian Jiu-Jitsu|
|Years active||retired in 2013|
|2003 São Paulo, Brazil||-66kg|
|2005 California, USA||-66kg|
|2007 New Jersey, USA||-66kg|
|2011 Nottingham, UK||-77kg|
|1997 Rio de Janeiro, Brazil||-76kg|
|1998 Rio de Janeiro, Brazil||-76kg|
|2000 Rio de Janeiro, Brazil||-76kg|
|Pan American Championship|
|2002 California, USA||-69kg|
|2004 California, USA||-69kg|
Leo Vieira began training Jiu-Jitsu at a very young age. He has won numerous medals, such as the Brazilian Jiu-Jitsu World Championships, Pan American Championships and the prestigious ADCC world championships.
CheckMat Jiu-Jitsu Team
One of the most successful teams in contemporary Brazilian Jiu-Jitsu, CheckMat's worldwide headquarters is in São Paulo, Brazil. CheckMat was established in 2008 by Leo and his brothers. Since its creation, Checkmat has become one of the top teams in Brazilian Jiu-Jitsu. Team CheckMat is the 2008 and 2009 NoGi World Champion Team. Team Checkmat also came in first for the Brazilian Nationals (Gi) 2010  and Brazilian Nationals (No-Gi) 2010.
- Gracie Mag Brazilian BJJ Nationals 2012 "In the stands Fábio Gurgel, Léo Vieira, Ramon Lemos, Rodrigo Cavaca and André Marola represented some of the traditional powerhouse teams that were in the running."
- https://web.archive.org/web/20120311050606/http://www.tatame.com.br/2009/11/15/Checkmat-conquista-o-bi-no-Mundial-No-Gi. Archived from the original on March 11, 2012. Retrieved March 29, 2012. Missing or empty
- Carlos Eduardo Ozório. "No-Gi Brazilian Nationals decisive day". Graciemag.com. Retrieved 2015-12-12.
- Carlos Eduardo Ozório. "Brazilian team champion issues provocation: "The dream of the grand slam is over"". Graciemag.com. Archived from the original on 2012-03-03. Retrieved 2015-12-12.