Οnassis Cultural Centre, Cultural center and concert hall in Athens, Greece.

The Onassis Cultural Centre is a cultural venue and concert hall in Athens with multiple floors and contemporary design. The facility provides specialized spaces for theater, music performances, and art exhibitions.

An international architecture competition drew 66 entries; the Paris firm Architecture Studio won with a facade of glass and white marble bands. Construction began in 2006 on a privately owned 3,000 m² plot and cost 80 million euros. The building opened in 2011, after the Onassis Foundation inaugurated it on 7 December 2010; the first production, directed by Michail Marmarinos, was dedicated to the construction workers.

The Onassis Stegi opened on 7 December 2010 with a production by Michael Marmarinos dedicated to the workers who built the building, inspired by Brecht's "Questions from a Worker Who Reads". Its stages have since shown works such as Nikos Karathanos's "Birds" (2016) and Dimitris Papaioannou's "The Great Tamer" (2017), alongside appearances by Tilda Swinton, Akram Khan and Brian Eno. Open discussions on human rights, democracy and the climate crisis are part of its programme.

The building occupies a full block on Leoforos Andrea Syngrou, within walking distance of the Acropolis Museum to the north. Four underground parking levels are reached by two separate double-helix ramps. The 200-seat open-air theatre and the rooftop restaurant Hytra share the top floor, seven levels and 27 metres above ground.

The building's seismic bearings were custom-made by Munich firm Maurer Söhne to withstand 0.24 g, above the 0.16 g required for Attica's zone. The facade's white marble bands, echoing ancient minimalism, reflect Attic light by day and let the interior glow through at night.