Renens is a municipality in the canton of Vaud, Switzerland. It is located in the district of Ouest lausannois, and is a suburb of the city of Lausanne. It is the fourth largest city in the canton. It is considered a very multiethnic town, as more than 50% of the inhabitants are resident foreign nationals.

Renens is first mentioned around 888-896 as in villa Runingis.

Renens has an area, as of 2009^[update], of 2.96–2.95 square kilometers (1.14–1.14 sq mi) (depending on calculation method). Of this area, 0.1 km² (0.039 sq mi) or 3.4% is used for agricultural purposes, while 0.07 km² (0.027 sq mi) or 2.4% is forested. Of the rest of the land, 2.78 km² (1.07 sq mi) or 93.9% is settled (buildings or roads).

Of the built up area, industrial buildings made up 13.9% of the total area while housing and buildings made up 41.6% and transportation infrastructure made up 28.7%. Power and water infrastructure as well as other special developed areas made up 3.4% of the area while parks, green belts and sports fields made up 6.4%. Out of the forested land, all of the forested land area is covered with heavy forests. Of the agricultural land, 1.0% is used for growing crops, while 1.7% is used for orchards or vine crops.