William, Bill or Billy Abbot/Abbott may refer to:

• William Abbot (actor) (1790–1843), English actor and theatrical impresario
• William Edward Abbott (1844–1924), Australian political figure; represented Electoral district of Upper Hunter 1889 to 1891
• William Abbott (cricketer) (1856–1935), English cricketer
• William Abbott (footballer) (fl. 1876–1893), English outside-left
• William Henry Abbott (1888–1974), Newfoundland merchant and politician
• William Alexander Abbott (1897–1974), American vaudeville and film actor, of Abbott and Costello
• William C. Abbott (c. 1817–1863), member of the Texas Senate
• William Hawkins Abbott (1819–1901), American oil producer and trader
• William J. Abbott (born 1962), American businessman and CEO of Great American Media
• William L. Abbott (1861–1951), American mechanical engineer
• William Louis Abbott (1860–1936), American physician and philanthropist
• William Osler Abbott (1902–1943), American physician noted as co-developer of Miller-Abbott tube
• Bill Abbott Jr. (born 1954), Canadian Olympic sailor and boatbuilder
• Billy Abbott, a character on the American daytime soap opera The Young and the Restless
• William Abbot (martyr) (bef 1576–1596), English Catholic martyr, executed along with William Knight
• William Abbot (politician) (fl. 1437), English politician
• William Wright Abbot (1922–2009), American archivist and historian

• William Abbotts (1736–1805), English landowner, co-founder of "Original Baths"
• All pages with titles containing William Abbott
• Abbott (surname)