Coordinates: 48°40′56″N 2°10′11″E / 48.6822°N 2.1698°E / 48.6822; 2.1698

Les Ulis is a commune in the Essonne department located in the southwestern suburbs (banlieue) of Paris, France. It is 23 km (14 mi) from the center of Paris.

Inhabitants of Les Ulis are known as Ulissiens.

Les Ulis is a new town located in the Île-de-France, in the south-west of the Parisian agglomeration and in the north-west of the Essonne department. It sits on the Cortabœuf plateau which dominates the Yvette valley, also known as the Chevreuse valley. It is 23km to the south-west of central Paris, 20km north-west of Évry and 14km to the south-east of Versailles.

The town is laid out in the form of a U, approximately three km by two km, and covers 680 hectares. Over 65% of the area is built-up, 17% is semi-rural and 16% is either rural or comprises communal green space. The French Institut Géographique National gives the co-ordinates of the town as 48°40'58" N and 02°09'55" E at the central point.

The source of the minor river Rouillon (river) is in the neighbouring town of Villejust, close to the communal border. The lowest point of the town, at the point where it meets Bures-sur-Yvette, is at an altitude of 87m. Most of the town is situated at an average altitude of over 150m. Its highest point is at 170m. The land on which it is built consists of clay, sand and millstone.

Laouni Mouhid, commonly known by his alias La Fouine (English: The Weasel) or Fouiskin (born December 25, 1981 in Trappes, Yvelines), is a French rapper of Moroccan origins from the city of Trappes, Yvelines in the Paris western suburbs. He is an established figure in French rap. La Fouine signed with Sony Records in 2003 and released his debut album, Bourré au son, in 2005. La Fouine released his second album, Aller-Retour, on March 12, 2007. The American beatmaker Focus produced four songs on the album. His most recent album, Mes Repères, was released on February 23, 2009 and is two times gold record in France. His new album, a double CD intitled "La Fouine Vs Laouni," released on February 14 for Valentine's Day, was inspired by the two sides of himself, through his career and experience of his daily life. The first one, La Fouine, a character he created to "entertain people, La Fouine is very cunning, materialistic, bad boy and so vulgar ... it's not really me" said the artist. The second one Laouni (his real name) talks about things he lived in his youth, so his rap is sincere and moving. The week of album's release, more than 25 621 copies were sold in France, a feat for a hip hop artist. He has also his own label "Banlieue Sale Music" and his own clothing line called "Street Swagg".