Marián Ostrčil (born 15 October 1980 in Bratislava) is a Slovak sprint canoer who has been competing since 1998.
In 1998, in Nyköping, Sweden, he became European junior champion in the individual Canadian canoe (C-1) 500m. In 2002 he won the European under-23 championship in Zagreb, Croatia in the same event.
At the ICF Canoe Sprint World Championships, Ostrčil won two medals with one silver (C-1 1000 m: 2007) and one bronze (C-1 5000 m: 2010). Competing in two Summer Olympics, he earned his best finish of seventh in the C-1 1000 m event at Athens in 2004.
Ostrčil is 190 cm (6'3") tall and weighs 90 kg (198 lbs). He is a member of the AŠK Dukla club in Trenčín where he is coached by Atlanta silver medallist Slavomír Kňazovický.