List of Famous people named William

William V of Montferrat also known regnally as William III of Montferrat while also referred to as William the Old or William the Elder, in order to distinguish him from his eldest son, William Longsword, was seventh Marquis of Montferrat from c. 1136 to his death in 1191. William was the only son of Marquis Renier I and his wife Gisela, a daughter of William I, Count of Burgundy and widow of Count Humbert II of Savoy. It seems likely, given that he was still fit enough to participate in battle in 1187, that William was one of his parents' youngest children.

William Stewart, 2nd Viscount Mountjoy, was an Anglo-Irish peer.

William Bernard, 12th Baron Petre "a pattern of charity and piety", was an enthusiastic builder of churches. To a greater or lesser extent, he was responsible for new churches in Brentwood, Chipping Ongar, Barking, Romford and Chelmsford and a mortuary chapel in the grounds of Thorndon Hall, as well as twice extending the chapel at Ingatestone Hall, which then served as parish church for the locality.

William James Perry is an American mathematician, engineer, businessman, and civil servant who was the United States Secretary of Defense from February 3, 1994, to January 23, 1997, under President Bill Clinton. He also served as Deputy Secretary of Defense (1993–1994) and Under Secretary of Defense for Research and Engineering (1977–1981).

William Stratford Dugdale DL was a British Tory politician.

Darwin William Duell was an American actor and singer. He was known for his roles as Andrew McNair in the musical 1776, Jim Sefelt in the 1975 film One Flew Over the Cuckoo's Nest, and Johnny the Shoe Shine Guy on the 1982 crime comedy series Police Squad!. Described as a short, odd-looking character actor with a Shakespearean background, he had many minor roles in plays, films, and TV series. His last work was a cameo in the 2003 film How to Lose a Guy in 10 Days.

William of Hauteville was one of the younger sons of Tancred of Hauteville by his second wife Fressenda. He is usually called Willermus instead of Wilelmus in Latin annals and so is often called Guillerm instead of Guillaume in French. He left Normandy around 1053 with his elder half-brother Geoffrey and full brother Mauger.

William Seymour, 2nd Duke of Somerset, was an English nobleman and Royalist commander in the English Civil War.