Palais des sports de Saint-Nazaire, Multi-purpose sports complex in Saint-Nazaire, France.

Palais des Sports de Saint-Nazaire is a multipurpose indoor venue designed for sporting competitions and public events. The building features a distinctive dome structure that serves as its defining architectural element and houses a single main arena for various activities.

The Grand Marais marsh was filled with 500,000 m³ of rubble and 600,000 m³ of sand from the Loire estuary before the first stone was laid in October 1963. Architects Vissuzaine, Longuet and Rivière, with city architect Joly, set the shell on 166 Franki piles. A contractor bankruptcy, budget trouble, bad weather and the strikes of 1968 stretched the work to seven years; the hall opened in February 1970 and was listed as a monument historique on 29 May 2019.

Nicknamed "La Soucoupe" for its saucer shape, the hall has hosted boxing (Roland Cazeaux vs Luc Rudi Haeck, 27 February 1976) and the Harlem Globetrotters on 27 May 2010. Since 1970 it has been given over almost entirely to sport, with only about three cultural or event functions a year.

The arena holds 2,200 fixed seats in the stands and can be configured for up to 3,500 people. It sits in a 52-hectare sports and leisure zone on the Grand Marais, so allow time to walk between the hall and its surroundings. Cultural or event programming is now limited to about three dates a year, so check what is on before travelling.

The marshy Grand Marais ground could not carry the shell on a simple raft foundation, so 166 Franki piles were driven to support external beams. The roof weighs only 12 kg/m², a sandwich of polyvinyl, polystyrene, hard isogyl board and aluminium held between two tri-directional meshes.