Willoughby is a surname. Notable people with the surname include:
Alex Willoughby, British footballer
Althea Willoughby (1904–1982), British artist
Barrett Willoughby (1901–1959), American writer
Bart Willoughby (born 1960), Pitjantjatjara (Indigenous Australian) musician
Benjamin Willoughby (1855–1940), Justice of the Indiana Supreme Court
Bill Willoughby (born 1957), American professional basketball player
Charl Willoughby (born 1974), South African cricketer
Charles A. Willoughby (1892–1972), American major general
Claude Willoughby (1898–1973), American baseball player
Francis Willoughby (disambiguation), several people called Francis Willoughby or Willughby
George Willoughby (disambiguation), several people
Henry Willoughby (disambiguation), several people
Holly Willoughby (born 1981), English television presenter
Hugh de Willoughby, English medieval theologian and university chancellor
Hugh Willoughby (disambiguation), several people
India Willoughby (born 1965), British newsreader
John Willoughby (disambiguation), several people
Kim Willoughby (born 1980), American volleyball player
Leonard Ashley Willoughby (1885–1977), British scholar of German literature
Lillian Willoughby (1916–2009), American peace activist
L. Jean Willoughby (1925–2015), American politician
Marlene Willoughby (born 1948), American pornographic actress
Meta Fust Willoughby (1887-1937) American composer who used the pseudonym Meta Schumann
Nesbit Willoughby (1777–1849), British Royal Navy rear admiral
Percival Willoughby (died 1643), MP for Nottinghamshire and businessman
Westel Willoughby Jr. (1769–1844), American politician
Westel W. Willoughby (1867–1945), American political theorist, twin brother of William F. Willoughby
William Willoughby (disambiguation), several people