Saint-Julien-en-Genevois (; ) is a subprefecture of the Haute-Savoie department in the Auvergne-Rhône-Alpes region in Eastern France.
Saint-Julien-en-Genevois is located right on the Swiss border some southwest of the city centre of Geneva and forms part of its metropolitan area.
The commune of Saint Julien-en-Genevois also consists of the following villages: Thairy, Crâche, Thérens, Norcier, Ternier, Lathoy.
In 2007, there were 4,491 jobs in Saint-Julien-en-Genevois and 5,401 active inhabitants. However, 46.1% of active inhabitants were working in neighbouring Switzerland. The unemployment rate stood at 10.6%, twice as high as in the neighbouring rural and residential communes.
Every summer, a rock-oriented music festival called "Guitare en Scène" is held in Saint-Julien-en-Genevois. Famous past performers include Sting and Carlos Santana.
Saint-Julien-en-Genevois has been twinned with Mössingen, Germany, since 13 January 1990.