The Olympic Indoor Hall (also known simply as the Indoor Hall) is the largest indoor venue in use for sporting events at the 2004 Summer Olympics in Athens, Greece. It is part of the Athens Olympic Sports Complex. The arena was used for artistic gymnastics and trampolining and also hosted the finals of the basketball matches at the games.

The arena seats up to 17,500 for the gymnastics events and 19,200 for the basketball games, though only 12,500 seats were made publicly available for the gymnastics. Construction of the building was completed on August 30, 2004, and it was officially opened on August 10, 2004, shortly before the beginning of the games. It is notable for the distinctive A-frame roof.