William, Will, Willie, Bill, or Billy Richardson may refer to:

• William Richardson (1656–1727), MP for Armagh and Hillsborough
• William Richardson (died 1755) (1690–1755), MP for Augher
• William Richardson (1710–1758), MP for Armagh
• William Richardson (1749–1822), MP for Armagh
• Sir William Richardson, 1st Baronet (died 1830), MP for Augher and Ballyshannon

• Bill Richardson (1947–2023), Governor of New Mexico, U.S. Secretary of Energy, Congressman; 2008 Presidential candidate
• Friend Richardson (William Richardson, 1865–1943), 25th governor of California
• H. L. Richardson (Hubert Leon "Bill" Richardson, 1927–2020), California state senator
• Willy Bo Richardson (born 1974), American artist
• William Richardson (Maryland politician) (1735–1825), Revolutionary War soldier
• William Richardson (Mississippi politician) (1951–1997), Mississippi politician and teacher
• William Richardson (South Carolina politician) (1743–1786), South Carolina politician
• William Adams Richardson (1821–1896), Treasury secretary
• William Alexander Richardson (1811–1875), U.S. senator from Illinois
• William B. Richardson (1874–1945), Minnesota state senator
• William Emanuel Richardson (1886–1948), U.S. representatives from Pennsylvania
• William Henry Richardson (1808–1878), Connecticut state legislator
• William M. Richardson (1774–1838), U.S. representative from Massachusetts, 1811–1814
• William Richardson (Alabama politician) (1839–1914), U.S. representative from Alabama, 1900–1914
• William P. Richardson (Ohio politician) (1824–1886), Republican politician from the state of Ohio, USA
• William P. Richardson (law school dean) (1864–1945), American co-founder and first Dean of Brooklyn Law School
• William P. Richardson (New York politician) (1848–1923), New York politician
• William S. Richardson (1919–2010), lieutenant governor of Hawaii
• William O. Richardson (born 1954), American politician
• William U. Richardson, lawyer and member of the Louisiana House of Representatives

• William Richardson (colonial administrator) (died 1829), Deputy Governor of Anguilla
• William Westbrooke Richardson (died 1771), High Sheriff of Sussex in 1770

• William Richardson (Cambridge University cricketer) (1861–1933), English cricketer with Cambridge University
• William Richardson (Worcestershire cricketer) (1894–1971), English cricketer with Worcestershire
• William Richardson (Derbyshire cricketer) (born 1938), English cricketer with Derbyshire
• William Richardson (New South Wales cricketer) (1866–1930), Australian cricketer with New South Wales
• Bill Richardson (athlete) (1903–1969), American Olympic runner
• William "Ginger" Richardson, known as W. G. Richardson (1909–1959), English footballer
• William Richardson (footballer) (1880–1903), Australian rules footballer
• Billy Richardson (footballer, born 1896) (1896–1959), English footballer
• Bill Richardson (footballer, born 1908) (1908–1985), English footballer
• Bill Richardson (footballer, born 1943), English footballer
• Billy Richardson (1920–2004), Irish soccer player
• Willie Richardson (1939–2016), American football wide receiver
• Bill Richardson (baseball) (1878–1949), American baseball player
• Willie Richardson (wrestler), member of Da Soul Touchaz
• Will Richardson (basketball) (born 1999), American basketball player
• Will Richardson (American football) (born 1996), American football player

• William Richardson (martyr) (1572–1603), beatified Roman Catholic martyr
• William Richardson (bishop) (1844–1915), Anglican Bishop of Zanzibar, 1895–1901

• William Richardson (antiquary) (1698–1775), English academic and antiquary
• William Richardson (classicist) (1743–1814), Scottish professor and scholar
• William Richardson (astronomer) (1796–1872), British astronomer
• William J. Richardson (1920–2016), American philosopher
• William C. Richardson (1940–2021), President of Johns Hopkins University, 1990–1995
• William D. Richardson (born 1951), Director of the UCL Wolfson Institute since 2012
• William Bebb Richardson (1912–2006), American mammalogist

• William Anthony Richardson (1795–1856), sea captain and early California entrepreneur
• William Blaney Richardson (1868–1927), American-Nicaraguan naturalist
• W. P. Richardson (trade unionist) (William Pallister Richardson, 1873–1930), British trade unionist
• William R. Richardson (1929–2023), U.S. Army general
• William R. Richardson (Medal of Honor) (1842–1873), Union Army soldier and Medal of Honor recipient
• William Richardson (songwriter), Tyneside songwriter
• Will Richardson (educator), author and blogger
• Bill Richardson (journalist) (1909–1986), British newspaper editor
• Bill Richardson (broadcaster) (born 1955), Canadian radio broadcaster and author
• Billy Richardson (Pony Express rider) (1834–1862)