Siemowit (Polish pronunciation: [ɕɛˈmɔvit], also Ziemowit [ʑɛˈmɔvit]) was, according to the chronicles of Gallus Anonymus, the son of Piast the Wheelwright and Rzepicha.

[1] He became the Duke of the Polans in the 9th century after his father, Piast the Wheelwright, son of Chościsko, refused to take the place of legendary Duke Popiel.

[2] According to a popular legend, Popiel was then eaten by mice in his tower on Gopło lake.

[3] The only mention of Siemowit, along with his son, Lestek, and grandson, Siemomysł, comes in the medieval chronicle of Gallus Anonymus.

[4] Siemowit's great-grandson, Mieszko I, was the first Christian ruler of Poland.