William Lancaster

William Lancaster may refer to:


 * William de Lancaster I, or William Fitz Gilbert, was a nobleman of the twelfth century in Northwest England
 * William Lancaster (Queen's) (1650–1717), English academic administrator and clergyman
 * William Lancaster (anthropologist) (1938–2022), British social anthropologist studying various Arab tribes and communities
 * William Lancaster (cricketer) (1873–1938), English cricketer
 * William Lancaster (politician) (1841–1929), English politician and benefactor
 * William H. Lancaster (born 1931), member of the California State Assembly
 * William Edward Lancaster (1909–2003), chief executive of the Royal Zoological Society of South Australia
 * Willie Lancaster, Scottish footballer
 * Bill Lancaster (1947–1997), American screenwriter
 * Bill Lancaster (aviator) (1898–1933), British aviator