Brazilian middle-distance runner
Osmar Barbosa dos Santos (born October 20, 1968, in Marilia) is a retired Brazilian middle distance runner who competed mostly over 800 metres. He started competing internationally around year 1996 and won a bronze medal at the 2004 World Indoor Championships.
| Year | Competition | Venue | Position | Event | Notes |
Representing  Brazil |
| 1995 | South American Championships | Manaus, Brazil | 1st | 4 × 400 m relay | 3:04.93 |
| 1996 | Ibero-American Championships | Medellín, Colombia | 2nd | 4 × 400 m relay | 3:04.28 |
| Olympic Games | Atlanta, United States | 33rd (h) | 400 m | 46.16 |
| 4th (h) | 4 × 400 m relay | 3:02.51 |
| 1997 | World Indoor Championships | Paris, France | 8th (h) | 4 × 400 m relay | 3:10.50 |
| 2000 | Olympic Games | Sydney, Australia | 20th (sf) | 800 m | 1:47.68 |
| 2002 | Ibero-American Championships | Guatemala City, Guatemala | 2nd | 800 m | 1:46.81 |
| 2003 | World Indoor Championships | Birmingham, United Kingdom | 12th (sf) | 800 m | 1:50.06 |
| South American Championships | Barquisimeto, Venezuela | 2nd | 800 m | 1:46.92 |
| Pan American Games | Santo Domingo, Dominican Republic | 2nd | 800 m | 1:49.63 |
| World Championships | Paris, France | 8th | 800 m | 1:46.28 |
| 2004 | World Indoor Championships | Budapest, Hungary | 3rd | 800 m | 1:46.46 |
| Ibero-American Championships | Huelva, Spain | 5th (h) | 800 m | 1:50.00 |
| Olympic Games | Athens, Greece | 22nd (sf) | 800 m | 1:48.23 |
| 2005 | World Championships | Helsinki, Finland | 20th (h) | 800 m | 1:47.74 |
| 2006 | World Indoor Championships | Moscow, Russia | 9th (h) | 800 m | 1:48.30 |
| Ibero-American Championships | Ponce, Puerto Rico | 1st | 800 m | 1:46.22 |
