Philipp Rüfer (full name Philipp Bartholomé Rüfer; 7 June 1844 – 15 September 1919) was a German composer, pianist, and music teacher of Walloon origin. He was born in Liège, Wallonia, Belgium, the son of the German organist Philipp Rüfer, who had moved to Belgium.
Rüfer graduated from the Liège Conservatory, where he studied with Étienne Soubre, and subsequently continued his training in Leipzig under Moritz Hauptmann. From 1869 he worked as a conductor in Essen. In 1871 he settled in Berlin, where he lived and worked for the rest of his life. He taught at the Stern Conservatory, the New Academy of Music, and, from 1881, the Scharwenka Conservatory, eventually returning to the Stern Conservatory. His pupils included Georgy Catoire, Heinz Tiessen, and Karl Krebs.
His most successful works included the opera Merlin (1887), based on Karl Lebrecht Immermann, as well as a symphony and a violin concerto whose style recalls early Richard Strauss. He also composed the overture Rubens, string quartets in E-flat major and D minor, the opera Ingo (1895), a suite for piano and cello, and numerous other chamber and organ works.