Gaynor is both a surname and a feminine given name. Notable people with the name include:
Surname:
Adam Gaynor (born 1963), American guitarist
Barrington Gaynor (born 1965), Jamaican footballer
Ciara Gaynor (born 1979), Irish camogie player
Dave Gaynor, English drummer
Gloria Gaynor (born 1949), American singer
J.B. Gaynor (born 1990), American actor
Janet Gaynor (1906–1984), American actress
Jessie Gaynor (1863–1921), American composer
Jock Gaynor (1928–1998), American actor
John A. Gaynor (1846-1915), American politician
Katie Gaynor (born 1977), Australian baseball player
Len Gaynor (born 1944), Irish hurling manager
Mel Gaynor (born 1960), British musician
Mitzi Gaynor (born 1931), American actress, singer and dancer
Ross Gaynor (born 1987), Irish footballer
Tommy Gaynor (born 1963), Irish footballer
William Jay Gaynor (1849–1913), mayor of New York City
Given name:
Gaynor Arnold, Welsh author
Gaynor Barnes (born 1961), English television journalist
Gaynor Faye (born 1971), English television actress
Gaynor Hopkins (born 1951), the birth name of Welsh singer Bonnie Tyler
Gaynor Lucas, minor character in the BBC soap opera EastEnders
Gaynor Rowlands (1883–1906), Edwardian actress of Welsh descent
