Île Seguin is an island on the Seine river between Boulogne-Billancourt and Sèvres, in the west suburbs of Paris, France. It has a surface area of approximately 11.5 hectares, and is positioned opposite Meudon, a short distance downstream from the Île Saint-Germain. Administratively Meudon and the island are included as part of Boulogne-Billancourt, on the river's right bank, rather than of Sèvres on the left bank.

Boulogne-Billancourt is a wealthy and prestigious commune in the western suburbs of Paris, France, located 8.2 km (5 mi) from the centre of Paris. It is a subprefecture of the Hauts-de-Seine department and thus the seat of the larger arrondissement of Boulogne-Billancourt. It is also part of the Métropole du Grand Paris. Boulogne-Billancourt includes one island in the Seine: Île Seguin.