Born in Berlin, Rudorff studied piano under Woldemar Bargiel from 1852 to 1857 before enrolling at the Leipzig Conservatory in 1859, where he studied under Ignaz Moscheles, Louis Plaidy, and Julius Rietz. He was also a private pupil of Moritz Hauptmann and Carl Reinecke.
In 1865 he became a piano teacher at the Cologne Conservatory, and he founded the Bach-Verein Köln in 1867. He moved to Berlin in 1869, and for four decades, to his retirement in 1910, was the head piano teacher at the Berlin Hochschule. He also conducted the Stern Gesangverein from 1880–90, succeeding Max Bruch.
His students included Fridtjof Backer-Grøndahl, Wilhelm Berger, Leo Blech, Gerard von Brucken Fock, Leopold Godowsky, Siegfried Ochs, Alexandre Rey Colaço, Clemens Schmalstich, Carl Schuricht and Alfred Sormann.
Among his works are: Symphony No. 1 in B flat, Op. 31; No. 2 in G minor, Op. 40; No. 3 in B minor, Op. 50; serenades for orchestra (Op. 20 in A; Op. 21 in G); three overtures, to Ludwig Tieck's Märchen vom blonden Ekbert (Op. 8); to Otto der Schütz (Op. 12); Romantische Ouverture (Op. 45); Ballade in 3 movements for orchestra (Op. 15); Variationen for orchestra (Op. 24); Romanze for violin and orchestra (Op. 41); Der Aufzug der Romanze (libretto by Ludwig Tieck) for solo, choir, and orchestra (Op. 18); Gesang an die Sterne (libretto by Friedrich Rückert) for six voices with orchestra; Herbstlied (Op. 43); String sextet in A (Op. 5); and many songs.
Rudorff also orchestrated Schubert's Fantasia in F minor; edited the full score of Weber's Euryanthe and the piano concertos and piano sonatas of Mozart; and published Weber's letters to Heinrich Lichtenstein (1900). His correspondence with Brahms and Joachim has also been published in collections of the latter two's letters.
- Nicolas Slonimsky, ed. (1958). "Rudorff, Ernst Friedrich Karl". Baker's Biographical Dictionary of Musicians (5th edition ed.). p. 1388.
- This article or an earlier version incorporates text from the 3rd edition (1919) of Baker's Biographical Dictionary of Musicians, a publication now in the public domain.
- The Mutopia Project has compositions by Ernst Rudorff
- Free scores by Ernst Rudorff at the International Music Score Library Project