Dudley Buck (March 10, 1839 – October 6, 1909) was an American composer, organist, and writer on music. He published several books, most notably the Dictionary of Musical Terms and Influence of the Organ in History, which was published in New York in 1882. He is best known today for his organ composition, Concert Variations on the Star-Spangled Banner, Op. 23, which was later arranged into an orchestral version.

Born in Hartford, Connecticut, Buck was the son of a merchant who gave him every opportunity to cultivate his musical talents. After attending Trinity College, for four years (1858–1862) he studied in Leipzig at the Leipzig Conservatory where he was a pupil of Louis Plaidy. He then pursued further studies in Dresden and Paris. On returning to America he held positions of organist in Hartford, Chicago (1869), and Boston (1871).

In 1875 Buck went to New York to assist Theodore Thomas as conductor of orchestral concerts, and from 1877 to 1902 was organist at Holy Trinity Church in Brooklyn. By this time he had become well known as a composer. His compositions included church music, a number of cantatas (Columbus (1876), Golden Legend (1880), Light of Asia (1885), etc.), a grand opera Serapis, a comic opera Deseret (1880), a symphonic overture Marmion, a symphony in E flat, and other orchestral and vocal works.

Buck also taught private music lessons throughout his career. Among his notable pupils were Paul Ambrose, William Howland, Daniel Protheroe, Harry Rowe Shelley, and Charles Sanford Skilton.