The Kursenieki language (Kursenieki: kursisk valuod, German: Nehrungskurisch; Latvian: kursenieku valoda; Lithuanian: kuršininkų kalba) or Curonian language of the Curonian isthmus (German: kurische Sprache der Kurischen Nehrung[3]) is a dialect of the Latvian language spoken by the Kursenieki of the Curonian Spit, a thin strip of land stretching between southwestern Lithuania and the Kaliningrad exclave of Russia.

The events of the first half of the 20th century and the Soviet annexation of East Prussia led to the near extinction of the language, making it severely endangered.

Several remaining native speakers live in Germany, having been expelled in the ethnic cleansing that took place in East Prussia after World War II.

Several pages of sample texts in Kursenieki language are included in the 1888 monograph Über die Sprache der preussischen Letten by Adalbert Bezzenberger and the 1927 monograph Kursenieku valoda by Juris Plāķis [lv], where they describe the language spoken by the inhabitants of the Curonian Spit.

[5] There is a 2002 documentary film Tarp aštuonių vėjų ("Amidst Eight Winds") by Arvydas Barysas about the endangered Kursenieki language.