Lyss is a municipality in the administrative district of Seeland in the Canton of Bern in Switzerland. It has a population of 11,000 people. About 84% of these people are Swiss German. Politically, Lyss can be called a city. The name "Lyss" comes from the local river Lyssbach.
On 1 January 2011, the old municipality of Busswil bei Büren was combined with Lyss.