William Ferguson may refer to:

• William Ferguson (tenor), operatic tenor, see The Tempest
• William Gouw Ferguson, Scottish painter of still life
• William J. Ferguson (1845–1930), American actor and witness to Abraham Lincoln's assassination
• Will Ferguson (born 1964), Canadian writer

• Bill Ferguson (American football) (born 1951), NFL linebacker
• Bill Ferguson (cricket scorer) (1880–1957)
• Willie Ferguson, Scottish footballer with Chelsea and Queen of the South
• Willie Ferguson (footballer), Scottish footballer with Celtic, Burnley and Manchester City
• William Ferguson (racing driver) (1940–2007), in Formula One competitions
• Billy Ferguson (1938–1998), Northern Irish footballer

• William Ferguson (1891–1961), NSW, Australia politician (1953–1961)
• William John Ferguson (1859–1935), NSW, Australia politician (1894–1904)

• Will Ferguson (Ontario politician) (1954–2011), Ontario, Canada politician
• William Ferguson (Manitoba politician) (1862–1936), Canadian politician

• Bill Ferguson (politician) (born 1983), Maryland state senator
• William Webb Ferguson (1857–1910), Michigan state representative

• William Ferguson (1800–1828), Irish soldier of Irish military diaspora, aide-de-camp to General Simon Bolívar in Hispanoamerican wars of Independence.
• William Ferguson (Australian Aboriginal leader) (1882–1950), Indigenous Australian leader
• William Ferguson (botanist) (1820–1887), British botanist and entomologist
• William Ferguson (engineer) (1852–1935), New Zealand civil engineering manager and consultant
• William Ferguson (historian) (1924–2021), Scottish historian
• William Ferguson (Los Angeles pioneer) (1822–1910), settler
• William Ferguson (Australian pioneer) (c. 1809–1892) early settler of South Australia
• William C. Ferguson (1930–2015), American telecommunications expert, chairman and CEO of NYNEX
• William R. Ferguson (1900–1967), leader of the Cosmic Circle of Fellowship, a UFO religion

• Sir William Fergusson, 1st Baronet (1808–1877), Scottish surgeon
• William Fergusson (physician) (1773–1846), Scottish inspector-general of military hospitals and medical writer
• William Fergusson (politician), NSW, Australia politician (1880–1887)
• William Scott Ferguson (1875–1954), Canadian–American historian, president of the American Historical Association
• Ferguson (name)