Ioanna Stamatopoulou (, born 17 June 1998) is a Greek water polo player, playing as a goalkeeper for Olympiacos and the Greece women's national team. As a player of Olympiacos, she won the 2014–15 LEN Euro League Women, the 2015 Women's LEN Super Cup and the 2014 Women's LEN Trophy. She was part of the Greek national team that won the silver medal at the 2018 European Championship in Barcelona and the bronze medal at the 2015 European Games in Baku. She started competing water polo in 2009.