Mark Hermanus Maria Veens (born 26 June 1978 in Venray, Limburg) is a freestyle swimmer from the Netherlands, who competed for his native country at three consequentive Summer Olympics, starting in 1996 in Atlanta, Georgia as a member of the 4×100 m freestyle (fifth place). Veens' finest hour came at the 1998 European Short Course Swimming Championships in Sheffield, where he ended up in second place in the 50 m freestyle. Half a year later, at the 1997 FINA World Swimming Championships (25 m) in Hong Kong, he won the bronze medal in the 50 m freestyle.