Syanno or Senno (Belarusian: Сянно, romanized: Sianno;[a] Russian: Сенно; Polish: Sienno; Lithuanian: Siano) is a town in Vitebsk Region, Belarus.

It is located 58 km (36 mi) southwest of Vitebsk on the southern shore of Senno Lake.

[2] Fairs were held there, and a lively hay market gave it its name (Russian: сено seno 'hay').

In 1924, Senno became part of the Byelorussian Soviet Socialist Republic.

During World War II, it was the site of a major tank battle in July 1941.