William Reynolds is the name of:
- William Reynolds (actor) (born 1931), American movie and television actor
- William Reynolds (footballer, born 1870) (1870–?), English football defender of the 1890s
- William Reynolds (footballer, born 1879) (1879–?), English football forward of the 1900s
- William Reynolds (industrialist) (1758–1803), English ironmaster, built Ketley Canal, 1787–1788
- William Reynolds (naval officer) (1815–1879), U.S. Navy rear admiral in the American Civil War
- William Reynolds (theologian) (1544–1594), or Reginaldus, English Catholic biblical translator and scholar
- William Reynolds (VC) (1827–1869), Scottish Victoria Cross recipient
- William A. Reynolds (1872–1928), American football player and coach
- William C. Reynolds (1933–2004), American engineer and physicist
- William D. Reynolds (1867–1951), American Southern Presbyterian missionary and Bible translator in Korea
- William E. Reynolds (1860–1944), Commandant of the United States Coast Guard
- William George Waterhouse Reynolds, British Member of Parliament for Leicester South, 1922–1923
- William H. Reynolds, real estate developer and former New York Senator; developed several prominent New York neighborhoods, including Coney Island's Dreamland and Long Beach
- William H. Reynolds (1910–1997), American award-winning film editor
- William Hayden Reynolds (1847–1935), Mayor of Orlando, Florida 1910–1913
- William Hunter Reynolds (1822–1899), New Zealand politician and businessman
- William James Reynolds, Member of Parliament for East Tyrone, 1885–1895
- William Neal Reynolds (1863–1951), American tobacco manufacturer