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

• 400 metres - 46.35 (1995)
• 800 metres - 1:44.87 (2000)

• Osmar dos Santos at World Athletics