Marek Matiaško (born 29 October 1977) is a former Slovak biathlete.
He was born in Bojnice. He participated at the 2002 Winter Olympics in Salt Lake City. At the 2006 Winter Olympics in Turin he placed 5th in the 20 km. He also represented Slovakia at the 2010 Winter Olympics in Vancouver.
Matiaško retired from the sport after the 2009–10 season.