Jörg Demus (born 2 December 1928, in St. Pölten) is an Austrian pianist.
At the age of six, Demus received his first piano lessons. Five years later, at the age of 11, he entered the Vienna Academy of Music, studying piano and conducting. His debut as a pianist came when he was still a student: at the age of 14, Demus played in the Brahms-Saal for the prestigious Gesellschaft der Musikfreunde. He graduated in 1945, then 17 years old, after which he continued to study conducting with Josef Krips and Hans Swarowsky. Demus studied in Paris with Yves Nat from 1951 to 1953. In 1953 he studied interpretation further with Wilhelm Kempff, Arturo Benedetti Michelangeli, and Edwin Fischer, and attended master classes with Walter Gieseking. In 1956 he won first prize at the Ferruccio Busoni International Piano Competition.
He has been active as a Lied accompanist and a chamber music partner, appearing with such singers as Elisabeth Schwarzkopf, Dietrich Fischer-Dieskau, Elly Ameling and Peter Schreier and string players like Josef Suk and Antonio Janigro. He has performed widely as a soloist both on modern and on historical instruments and has collaborated with Paul Badura-Skoda on the concert platform and in a book on the interpretation of Beethoven's piano sonatas. In 1974, Demus performed for the Peabody Mason Concert series in Boston. Demus played Romantic works quite often; he took on the part of accompanist and performed in chamber music ensembles. Among his students is the pianist Domenico Piccichè.
Demus is also a composer, chiefly of music for the piano, chamber music and songs, composing in a generally conservative style. Recorded works include a recital of chamber music for cello and piano taking their inspiration from the poems of Paul Verlaine and the later music of Robert Schumann.
He received the Mozart Medal of the Mozartgemeinde Wien in 1979.