Sheena Tosta (née Johnson; born October 1, 1982) is an American track and field athlete who competes in the 400 metres hurdles. Her personal best time is 52.95 seconds, achieved in July 2004 in Sacramento. She won a silver medal in the Women's 400 metre hurdles at the 2008 Olympic Games. She finished fourth at the 2004 Summer Olympics and eighth at the 2006 World Athletics Final. She represented her country at the World Championships in Athletics in 2007 and 2009.