Wolf studied at the Vienna Conservatory (1875–77) but had a moody and irascible temperament and was expelled from the conservatory following his outspoken criticism of his masters. In 1875 he met the composer Richard Wagner, from whom he received encouragement. He met Johannes Brahms in 1879, and from him also he received encouragement and the urging to broaden his musical focus and his career. He was also a friend of Gustav Mahler (Mahler, Gustav) as a young man. In the late 1870s Wolf apparently contracted the syphilis that was to cripple and kill him. In the repeated relapses of the disease, Wolf would enter deep depressions and was unable to compose, but during remissions he was radiant and highly inspired. In 1883 Wolf became music critic of the Wiener Salonblatt; his weekly reviews provide considerable insight into the Viennese musical world of his day.

His early songs include settings of poems by J.W. von Goethe, Nikolaus Lenau, Heinrich Heine, and Joseph von Eichendorff. In 1883 he began his symphonic poem Penthesilea, based on the tragedy by Heinrich von Kleist. From 1888 onward he composed a vast number of songs on poems of Goethe, Eduard Friedrich Mörike, and others. The Spanisches Liederbuch (“Spanish Songbook”), on poems of P.J.L. von Heyse and Emanuel von Geibel, appeared in 1891, followed by the Italienisches Liederbuch (part 1, 1892; part 2, 1896). Other song cycles were on poems of Henrik Ibsen and Michelangelo. His first opera, Corregidor (1895; composed on a story by Pedro Antonio de Alarcón), was a failure when it was produced at Mannheim in 1896; a revised version was produced at Strasbourg in 1898. His second opera, Manuel Venegas, also after Alarcón, remained unfinished.

Wolf 's reputation as a song composer resulted in the formation in his lifetime of Wolf societies in Berlin and Vienna. Yet the meagre income he derived from his work compelled him to rely on the generosity of his friends. In 1897, ostensibly following upon a rebuke from Mahler but actually on account of growing signs of insanity and general paresis, he was confined to a mental home. He was temporarily discharged in 1898, but soon afterward he unsuccessfully attempted to commit suicide, and in October 1898 he requested to be placed in an asylum in Vienna.

Wolf wrote about 300 songs, many published posthumously. Of his first 100—from his early years—he only counted a handful worthwhile. But his output in the mature years was supremely original, in the finest tradition of the German lied. Wolf excelled at creating vocal melodic lines that express every emotional nuance of a given poetic text. The atmosphere of his songs ranges from tender love lyrics to satirical humour to deeply felt spiritual suffering. The vocal melodic line is subtly combined with strikingly original harmonies in the piano accompaniment, resulting in Wolf's remarkable fusion of music and speech. His instrumental works were more interesting for their underlying ideas than for their execution; they included the Italian Serenade for orchestra (1892; a transcription of the serenade for string quartet of 1887).