Seth Calvisius Free sheet music
- Born: 21st February 1556
- Died: 24th November 1615
- Birthplace: Gorsleben in present-day Thuringia, Germany
Sethus Calvisius or Setho Calvisio, originally Seth Kalwitz (21 February 1556 – 24 November 1615), was a German music theorist, composer, chronologer, astronomer, and teacher of the late Renaissance.