The Kashubians, also known as Cassubians or Kashubs, are a Lechitic ethnic group native to the historical region of Pomerania, including its eastern part called Pomerelia, in north-central Poland. Their settlement area is referred to as Kashubia. They speak the Kashubian language, which is classified as a separate language closely related to Polish.

Lechites, also known as the Lechitic tribes, is a name given to certain West Slavic tribes who inhabited modern-day Poland and eastern Germany, and were speakers of the Lechitic languages. Distinct from the Czech–Slovak subgroup, they are the closest ancestors of ethnic Poles and of Pomeranians, Lusatians and Polabians.