Ségny (French pronunciation: [seɲi]), also written Segny, is a commune in the Ain department in eastern France.

Ségny is situated in the east of the department, in a district of the Lake Geneva / River Rhône basin known as the Pays de Gex.

A local bus service connects Ségny to Geneva city centre, which is some 13 km (8.1 mi) away.

Ségny became a member of the Pays de Gex Community of Communes on 1 January 1996.

The commune is bordered by Cessy to the north, Versonnex to the east, Prévessin-Moëns and Ornex to the south, and Échenevex and Chevry to the west.