Martin Dematteis (born 24 May 1986) is an Italian male mountain runner and sky runner, one time senior individual European champion at European Mountain Running Championships (2016).
He won a bronze medal in the sport of athletics at senior level with the national team at the 2009 European Cross Country Championships held in Dublin, Ireland.
He won 8 medals at the World Mountain Running Championships (all with the national team) and 4 at individual level at the European Mountain Running Championships. He also competed at one edition of the IAAF World Cross Country Championships at senior level in 2010.
His twin brother Bernard Dematteis is also a mountain runner.