Sir William Sterndale Bennett (13 April 1816 – 1 February 1875) was an English composer, pianist, conductor and music educator.
At the age of ten Bennett was admitted to the Academy of Music (from 1830 the Royal Academy of Music) in London, where he remained for ten years. By the end of this time, he had begun to make a reputation as a concert pianist, and his compositions received high praise. Among those impressed by Bennett was the German composer Felix Mendelssohn, who invited him to Leipzig, Germany. There Bennett became friendly with Robert Schumann, who shared Mendelssohn's admiration for the Englishman's compositions. Bennett spent three winters composing and performing in Leipzig.
In 1837 Bennett returned to England. He taught at the Royal Academy for twenty years, later also teaching at Queen's College, London. For most of the 1840s and 1850s he composed little, although he performed as a pianist and directed the Philharmonic Society for ten years. In 1858 he returned to composition, but his later works were considered old-fashioned and did not arouse as much enthusiasm as his youthful compositions had done. He was professor of music at the University of Cambridge from 1856 to 1866, and principal of the Royal Academy from 1866 until his death.