Lyss (German pronunciation: [ˈliːs]) is a municipality in the Seeland administrative district in the Canton of Bern in Switzerland. On 1 January 2011, the former municipality of Busswil bei Büren was merged with Lyss.

Lyss is first mentioned in 1009 as Lissa.

The oldest traces of humans in Lyss include neolithic, Bronze Age and Hallstatt culture items scattered around the municipality. One of the best preserved items is a 6th-century BC Etruscan bronze statue. Roman era bricks have been found in Kirchhübeli along with early medieval and medieval tombs and the remains of a Carolingian church.