Iomar do Nascimento (born 8 April 1966), known as Mazinho, is a Brazilian football manager and former player, as well as the former head coach of Greek club Aris.
A former midfielder, Mazinho played 35 internationals for Brazil national team, winning the 1989 Copa América, 1994 FIFA World Cup and the Silver medal at the 1988 Olympics.
He was also named in the squads for the 1990 World Cup and 1991 Copa América.