William Parker may refer to:
Entertainment
William Parker (musician) (born 1952), American jazz double bassist
William Parker (screenwriter) (1886–1941), American screenwriter
William Parker (Private Practice), character in the series TV Private Practice
William Atticus Parker, (born 2004), American filmmaker and actor
Bill Parker (broadcaster) (William Parker, 1928–2019), American broadcaster
Bill Parker (comics) (William Lee Parker, 1911–1963), American comic book writer and editor
Military
William Parker (privy counsellor) (c. 1465–1510), privy counsellor and standard-bearer to King Richard III
William Parker (privateer) (died 1617), English captain and privateer, and also mayor of Plymouth
Sir William Parker, 1st Baronet, of Harburn (1743–1802), British admiral
Sir William Parker, 1st Baronet, of Shenstone (1781–1866), British admiral
William Harwar Parker (1826–1896), United States Navy officer
William Parker (Medal of Honor) (1832–?), American Civil War sailor and Medal of Honor recipient
William Albert Parker, American Civil War Union Navy commander of James River forces
Politicians
William Parker (died 1403), member of parliament (MP) for City of London
William Parker (died 1421), MP for Hertfordshire
William Parker (fl.1410), MP for Great Yarmouth
William Parker, 4th Baron Monteagle (1575–1622), English politician
William H. Parker (politician) (1847–1908), US representative from South Dakota
William Parker (Boston) (1793–1873), businessman and politician in the United States
William Parker (MP for West Suffolk) (1802–1892), British Member of Parliament for West Suffolk, 1859–1880
William Parker (Oregon politician), member of the Oregon Territorial Legislature, 1850
William T. Parker (1928–2014), member of the Virginia Senate and House of Delegates
Religion
William Parker (priest, died c. 1631), rose to archdeacon in two dioceses
William Parker (priest, died 1802) (c.1749–1802), Anglican controversialist
William Parker (bishop) (1897–1982), bishop of Shrewsbury in the Church of England
Sports
William Parker (Oxford University cricketer) (1832–1873), English cricketer
William Parker (New Zealand cricketer) (1862–1930), New Zealand cricketer
William Parker (MCC cricketer) (1886–1915), English cricketer
William Parker (bowls) (1892–1979), English bowls player
Will Parker (rugby union) (1873–1955), rugby union player
Sir William Parker, 3rd Baronet (1889–1971), British rower and Olympic medalist
Smush Parker (born 1981), American basketball player
Tony Parker (William Anthony Parker II, born 1982), French basketball player
Billy Parker (baseball) (William David Parker, 1942–2003), American baseball player
Billy Parker (gridiron football) (William Parker V, born 1981), American football linebacker
Willie Parker (offensive lineman) (William Nolen Parker, born 1948), American football player
Other people
William Parker (early settler) (1618–1686), settler in the Connecticut colony
William Parker (builder) (1800–1854), St. John's, Newfoundland builder
William Parker (abolitionist) (1821–1891), anti-slavery activist and freedom fighter
William Parker (glassmaker) (?–1817), American glassmaker and inventor
William Kitchen Parker (1823–1890), British physician and comparative anatomist
William Parker (master) (1870–1953), Australian barrister in New South Wales
William Belmont Parker (1871–1934), United States editor
William H. Parker (physicist) (1941–), American physicist
William H. Parker (police officer) (1905–1966), chief of the Los Angeles Police Department
William Riley Parker (1906–1968), American scholar of John Milton
William Vann Parker (1901-1987), American mathematician
Bill Parker (inventor) (William P. Parker), American artist, scientist, and entrepreneur
Will Parker (judge), American judge and lawyer