Lucens (French pronunciation: [lysɑ̃s]) is a municipality in the Broye-Vully District in the canton of Vaud in Switzerland . In 2017 the former municipalities of Brenles , Chesalles-sur-Moudon , Cremin , Forel-sur-Lucens and Sarzens merged into the municipality of Lucens.

Lucens is first mentioned in 964 as in villa Losingus. It was formerly known by the German name Losingen.

In 1969 the Lucens reactor , an underground nuclear reactor, began operations. It was a pilot project to test a heavy-water moderated, carbon dioxide gas-cooled reactor.