Ernő Dohnányi or (native form) Dohnányi Ernő (July 27, 1877 – February 9, 1960) was a Hungarian composer, pianist and conductor. He used a German form of his name, Ernst von Dohnányi, on most of his published compositions. The "von" implies nobility, and, according to the biography by his third wife, his family was ennobled in 1697 and given a family crest, which she describes in some detail.

Dohnányi's compositional style was personal, but very conservative. His music largely subscribes to the Neoromantic idiom. Although he used elements of Hungarian folk music, he is not considered a nationalist composer like Béla Bartók or Zoltán Kodály. Some characterize his style as traditional mainstream Euro-Germanic in the Brahmsian manner (structurally rather than the way the music actually sounds) rather than specifically Hungarian, while others hear very little of Brahms in his music, the best of which may be his Serenade in C major for string trio, Op. 10 (1902) and Variations on a Nursery Tune for piano and orchestra, Op. 25 (1914).