The Treaty of Dovydiškės (; ), Daudiske, or Daudisken was a secret treaty signed on May 31, 1380 between Jogaila, the Grand Duke of Lithuania, and Winrich von Kniprode, the Grand Master of the Teutonic Knights. The treaty was directed against Jogaila's uncle Kęstutis and its effect was to precipitate the Lithuanian Civil War (1381–1384).