Herbert Thomas Sullivan (13 May 1868 – 26 November 1928), known as "Bertie", was the nephew, heir and biographer of the British composer Arthur Sullivan. He grew up as his uncle's ward and worked briefly as an engineer. After his uncle's death, Sullivan became active in charitable work. He was co-author of a 1927 biography of Arthur Sullivan, well regarded in its day, but later discredited because of its suppression of the composer's diary entries that mentioned his gambling and philandering.
Sullivan inherited many of his uncle's papers and original music manuscripts. He left most of these to his wife, who died in 1957, and they finally were sold to collectors in 1966.