• Willie Watson (musician) (born 1979), American old-time and folk musician
• Billy Watson (actor) (born 1923), actor
• William Watson (actor) (1938–1997), American actor
• William Watson (poet) (1858–1935), English poet
• William Watson (songwriter) (1794–1840), Tyneside concert hall singer and songwriter
• William Watson (writer) (1930–2005), also known as Bill Watson, Scottish writer

• W. Marvin Watson (1924–2017), U.S. Postmaster General
• William Watson (16th century MP), MP for the City of York
• William Watson (Australian politician) (1864–1938), Australian politician
• William Watson, mayor of Rockford, Illinois, 1878–79
• Sir William Henry Watson (1796–1860), Baron of the Exchequer
• William John Watson (1839–1886), New South Wales politician
• William Watson (New South Wales politician) (1815–1877), New South Wales politician
• William McLean Watson (1874–1962), MP for Dunfermline Burghs, 1922–1931 and 1935–1950
• William T. Watson (1849–1917), American banker and Governor of Delaware

• William Watson, Baron Thankerton (1873–1948), Scottish judge
• William Watson, Baron Watson (1827–1899), Scottish judge

• William Watson (sergeant) (1826–1906), author and soldier in the Confederate States Army
• William Watson (surgeon) (1837–1879), surgeon in the 105th Regiment of Pennsylvania Volunteers during the American Civil War
• William E. Watson, military historian
• William H. Watson (1815–1846), Mexican–American War soldier from Maryland
• William Walker Russell Watson (1875–1924), decorated Australian Colonel of World War I
• William Thornton Watson (1887–1961), New Zealand officer in the Australian Imperial Force

• William Watson (botanist) (1858–1925), British botanist and horticulturalist
• William Watson (scientist) (1715–1787), English physician and scientist
• William Watson (physician) (1744–1824), English physician and naturalist, son of William Watson (1715–1787)
• William Watson (surveyor and scientist) (1784–1857), cartographer and sundial-maker from Seaton Ross
• William Weldon Watson (1899–1992), American nuclear physicist
• William Watson (physicist) (1868–1919), British physicist
• William Livingstone Watson (1835–1903), Scottish East India merchant and astronomer

Association football

• Bill Watson (footballer) (1899–1969), English footballer in the 1920s–30s
• Billy Watson (footballer, born 1890) (1890–1955), English international footballer with Burnley, 1908–1925
• Billy Watson (footballer, born 1893) (1893–1962), English footballer with Huddersfield Town, 1912–1927
• Billy Watson (Scottish footballer) (died 1950), Bradford City A.F.C. footballer, 1921–1931
• Billy Watson (soccer), Scottish-American footballer in the 1920s–30s
• Jimmy Watson (footballer, born 1914) (1914–1979), aka Bill Watson (William James Boyd Watson), English footballer in the 1930s
• William Watson (footballer) (fl. 1903–1909), Lincoln City footballer active in the 1900s
• William Watson (footballer, born 1900) (1900–?), Scottish footballer (Dumbarton FC)
• William Watson (Scottish footballer) (fl. 1898), Scottish footballer (Falkirk FC and Scotland)
• Willie Watson (English cricketer) (1920–2004), English cricketer and footballer
• Willie Watson (footballer, born 1910), Scottish footballer (Hibernian, Ayr United)
• Willie Watson (footballer, born 1949), Scottish footballer (Manchester United, Motherwell)
• Graham Watson (footballer, born 1949), English footballer, aka "Willie" Watson

Cricket

• Bill Watson (cricketer) (born 1931), Aus