Kurt Werner Friedrich Reidemeister (October 13, 1893 - July 8, 1971) was a mathematician born in Brunswick, Germany. He received his doctorate in 1921 with a thesis in algebraic number theory. In 1923 he was appointed assistant professor at the University of Vienna. While there he became familiar with the work of Hahn and Wirtinger. In 1925 he became full professor at Königsberg, where he stayed until 1933, when he was forced to leave because of his opposition of the Nazis.

Reidemeister's interests were mainly in combinatorial group theory, combinatorial topology, and the foundations of geometry. His books include Knoten und gruppen (1926), Einführung in die kombinatorische Topologie (1932), and Knotentheorie (1932). He is known for Reidemeister moves (see Knot theory) and Reidemeister torsion.