Lestek (also Leszek, Lestko) was the legendary second duke of Poland, and son of Siemowit, born c. 870–880. Although proof of his actual existence is unclear, if he did exist, he must have been an influential person, because the tribes that lived in present-day Poland were known as Lestkowici.
The origin of his name is not known, it can be derived from the old Polish word lście which means "crafty". It is believed this is a diminutive of the Slavic name Lścimir or Lścisław. Lestek's wife (or wives or consorts) is unknown. A theory by Stanisław Zakrzewski claims Lestek (or Lestko) could have been married to a Moravian princess. Another theory (inferred from the descriptions of a Belgian chronicler from the 14th century) is that a Saxon princess could have been Lestek's wife and that they had a son, Ewraker, later the Bishop of Leodium. Lestko's son, Siemomysł, was the next ruler of the early pagan Polish state.