Nidau is a municipality in the district of Nidau in the canton of Bern in Switzerland.

Although the official language is German, a high minority of French speakers (20%) live in Nidau,which has since long been offering them the right to send their children to the French speaking schools of it sister city Biel/Bienne, the city of Nidau supporting the whole financial charge.

The main and the historic part of Nidau have been on an artificial island since the Jura water correction, created by the Nidau-Büren canal, the river Suze in French or Zihl in German and the lake's shore.