Lycabettus Theatre, Open-air amphitheater on Mount Lycabettus, Greece

Lycabettus Theatre is an open-air theatre in the Kolonaki district on the eastern slope of Lycabettus Hill, built into the hollow left by a quarry that closed in 1919. Architect Takis Zenetos designed a light metal shell set within the quarry void; it seats 3,000 spectators, though 5,000 were originally planned.

The Lycabettus quarry closed in 1919, and on 7 August 1939 Takis Mouzenidis directed Kleist's Penthesilea there for the EON and the Royal Theatre. The present theatre was built in 1964–65 by architect Takis Zenetos after Anna Synodinou leased the site for twenty years. Closed as structurally unsafe from June 2013, it was renovated by the City of Athens and reopened in September 2023.

The theatre is named after Anna Synodinou, the actress who leased the quarry in 1964 and ran the venue for years. Its stage has hosted Dimitris Mitropanos, Michalis Hatzigiannis, Marios Frangoulis, Cesária Évora, Nina Simone, Morrissey, The Dandy Warhols and Pink Martini. Since September 2023 it again serves as a summer stage of the Athens Epidaurus Festival.

The venue is accessible by funicular railway from Aristippou Street in Kolonaki, making it easy to reach the hilltop location. It's wise to arrive early for performances to secure good seating and take in the views from the surrounding mountain area.

The quarry on Lycabettus stopped operating in 1919, and the hollow it left was later used for open-air performances under the 4th of August Regime. The first theatrical performance there was Kleist's Penthesilea on 7 August 1939, directed by Takis Mouzenidis, produced by EON and the Royal (National) Theatre.