The Basilica of Saint-Denis is a large former medieval abbey church and present cathedral in the commune of Saint-Denis, a northern suburb of Paris. The building is of singular importance historically and architecturally as its choir, completed in 1144, is widely considered the first structure to employ all of the elements of Gothic architecture.

Saint-Denis is a commune in the northern suburbs of Paris, France. It is located 9.4 km (5.8 mi) from the centre of Paris. Saint-Denis is the second most populated suburb of Paris, with a population of 113,116 at the 2020 census. It is a subprefecture of the department of Seine-Saint-Denis, being the seat of the arrondissement of Saint-Denis. It is also part of the Métropole du Grand Paris.