William Johnson may refer to:
Entertainment
- Bunk Johnson (William Gary Johnson, 1879–1949), American jazz musician
- William Johnson (artist) (1901–1970), African–American painter of the Harlem Renaissance
- William Johnson (actor) (1916–1957), American actor
- William Manuel Johnson (1872–1972), American jazz musician
- William L. Johnson, American actor and musician
- William Allen Johnson (1816–1901), organ builder, Johnson Organs
- Zip the Pinhead (William Henry Johnson, 1842–1926), circus entertainer
Law
Military
Politics
U.S.
- William A. Johnson Jr. (born 1942), mayor of Rochester, New York
- William Cost Johnson (1806–1860), Maryland Congressman
- William Daniel Johnson (born 1954), American white nationalist, attorney, and perennial candidate
- William E. Johnson (Nebraska), Lieutenant Governor of Nebraska
- William E. Johnson (1862–1945), American temperance movement leader
- William Elting Johnson (1837–1912), New York politician
- William F. Johnson (1819–?), mayor of Lynn, Massachusetts
- William Johnson (Seneca County, NY) (1821–1875), New York State Senator and Civil War colonel
- William M. Johnson (1847–1928), New Jersey state senator
- William Richard Johnson (1875–1938), Illinois Congressman
- William Samuel Johnson (1727–1819), United States Founding Father
- William Wallace Johnson (1813–1900), Wisconsin State Assemblyman
- William Ward Johnson (1892–1963), U.S. Representative from California
- William Wartenbee Johnson (1826–1887), Ohio politician and judge
U.K.
- William Johnson (by 1523 – 1553 or later), MP for Kingston–upon–Hull
- William Augustus Johnson (1777–1863), English soldier and MP
- William Johnson (Liberal-Labour politician) (1849–1919), English coal miner, trade unionist and Liberal–Labour politician
- William Johnson (trade unionist) (1866–?), English trade union leader and socialist activist
- William Johnson (MP for Bedford) (by 1513–1558), MP for Bedford and New Woodstock
Australia and Canada
Religion
Science
Sports
- William Johnson (baseball) (1848–1909), American baseball player
- William Johnson (cricketer, born 1884) (1884–1941), Australian cricketer
- William Johnson (cricketer, born 1962), English cricketer
- William Johnson (handballer) (born 1953), American Olympic handball player
- William Johnson (rugby league), rugby league footballer of the 1930s for Wales, and Huddersfield
- William Johnson (swimmer) (1947–2005), American freestyle swimmer at the 1968 Summer Olympics
- William Johnson (wrestler) (1901–1928), American wrestler
- William "Hootie" Johnson (1931–2017), American golfer
- C. William Johnson (1917–1993), American skeleton racer
- Judy Johnson (William Julius Johnson, 1899–1989), American baseball player
- Skinny Johnson (William C. Johnson, 1911–1980), American basketball player
Other uses
- William Johnson (author) (born 1931), Canadian journalist and author
- William Johnson (barber) (1809–1851), successful free African American barber
- William Johnson (historian) (1909–1992), American journalist, sometimes credited Willliam W. Johnson
- William Johnson (police officer), English police officer
- William B. Johnson (mathematician) (born 1944), American mathematician
- William D. Johnson (CEO) (born 1954), American Chairman and CEO of Progress Energy
- William D. Johnson (journalist), American journalist and labor activist
- William Ernest Johnson (1858–1931), British logician
- William Henry Johnson (valet) (died 1864), President Abraham Lincoln's barber and valet
- William Johnson Cory (1823–1892), English educator and Uranian poet
- William R. Johnson (born 1949), chairman, president, and chief executive officer of the H. J. Heinz Company
- William Templeton Johnson (1877–1957), San Diego architect
- William Woolsey Johnson (1841–1927), American mathematician
- William R. Johnson Coliseum, an arena in Nacogdoches, Texas