Yaakov (Yasha) Rosenfeld (February 16, 1948 – July 21, 2002) was a condensed-matter theorist who made outstanding contributions to the statistical mechanics of liquids and dense plasmas. He was a leading figure in theories of liquids and his fundamental measure approach to classical density functional theory has been a very significant contribution to the subject. He received the Humboldt Prize, which is Germany's highest research award for foreign scientists and scholars in all disciplines.