Jonathan Powell (born 1969) is a British pianist and self-taught composer.
He was a student of Denis Matthews and Sulamita Aronovsky. He made his performing debut at the age of 20 in the Purcell Room in London.
His repertoire is broad and ranges from Bach to many contemporary works (he is associated with composers as varied as Michael Finnissy, John White, Ambrosini, Staud and Sirodeau). He specialises in the late Romantic era, and made his first acquaintance with Sorabji's music, with which he has since become strongly associated, in 1984 through the radio broadcasts of Yonty Solomon and through the scores, a handful of which were then still published and available through Oxford University Press. He was encouraged to contact the composer, and obtained copies of several later works which he premiered starting in 1990, and has been recording and performing regularly.
He has played Sorabji's four-hour Opus clavicembalisticum (1929–30) at several concerts and both performed and premiered other works by Sorabji, including the four-and-a-half-hour Piano Symphony No. 6, Symphonia claviensis (1975–76) and the seven-hour Sequentia cyclica super "Dies irae" ex Missa pro defunctis (1948–49). He has also recorded CDs, of Sorabji's music and of others, for the Altarus, Largo, , ASV and Danacord labels, including works by Alexander Goldenweiser, Joseph Marx, Alexander Krein, and others.
Powell has also contributed to The New Grove Dictionary of Music and Musicians. He is also the author of many editions of various composers' sheet music.