The Olympic Stadium of Athens "Spyros Louis" is a sports stadium in Marousi, in the north section of Athens, Greece. With a total capacity of 75,000, it is the largest sports venue in Greece. It is a part of the Athens Olympic Sports Complex (OAKA) and is named after the first modern Olympic marathon gold medalist in 1896, Spyros Louis. It is owned and operated by the Hellenic Olympic Committee. The stadium served as the main stadium during the 2004 Summer Olympics and the 2004 Summer Paralympics, including the opening and closing ceremonies.

Spyridon Louis, commonly known as Spyros Louis, was a Greek water carrier who won the first modern-day Olympic marathon at the 1896 Summer Olympics. Following his victory, he was celebrated as a national hero.