Marios Kapotsis (born 13 September 1991) is a Greek water polo player. He is part of Greece men's national water polo team that competes at the 2017 World Aquatics Championships in Budapest. At club level, Kapotsis currently plays for NC Vouliagmeni. From 2012 to 2014 he played for Olympiacos, with whom he won 2 Greek Championships and 2 Greek Cups. In August 2021, he won the silver medal with Greece in the water polo tournament at the 2020 Summer Olympics.