Daniel Vacek (born 1 April 1971) is a former tennis player from Czechoslovakia and the Czech Republic who turned professional in 1990. He reached the quarterfinals of the 1995 Paris Masters, the 1998 Canada Masters and the 1998 Cincinnati Masters, and achieved a career-high singles ranking of World No. 26 in January 1996.Vacek represented his native country at the 1996 Summer Olympics in Atlanta, Georgia, where he was defeated in the second round.