William, Bill, or Billy Barlow may refer to:
Religion William Barlow (bishop of Chichester) (c. 1498–1568), English cleric William Barlow (bishop of Lincoln) (died 1613), English Anglican priest and courtier William Barlow (archdeacon of Salisbury) (died 1625), Welsh churchman and writer on magnetism William Rudesind Barlow (1585–1656), English Benedictine monk William Barlow (dean of Peterborough) (1833–1908), Anglican priest
Others William Henry Barlow (1812–1902), English civil engineer William Barlow (pioneer) (1822–1904), American pioneer in Oregon William Barlow (vice-chancellor) (1834–1915), Irish-Australian lawyer and academic William Barlow (geologist) (1845–1934), English geologist Billy Barlow (1870–1963), Canadian ice hockey player Bill Barlow (1931–2020), Canadian politician in Ontario William K. Barlow (1936–2022), American politician in Virginia
Other uses William Barlow House, American historic building in Clackamas County, Oregon William V. N. Barlow House, American historic building in Albion, New York