Fritz Mackensen (born 8 April 1866 in Greene, near Kreiensen, Duchy of Brunswick – 12 May 1953 in Bremen) was a German painter of the Düsseldorf school of painting and Art Nouveau.
He was a friend of Otto Modersohn and Hans am Ende, and was one of the co-founders of the artists' colony at Worpswede.
From 1933 to 1935 he was head of the Nordische Kunsthochschule in Bremen (today's University of the Arts Bremen).