Ayer is a surname. Notable people with the surname include:
A. J. Ayer (1910–1989), British philosopher Caleb Ayer (1813–1883), American politician Claire D. Ayer (born 1948), Vermont politician David Ayer (born 1968), American screenwriter Donald B. Ayer (born 1949), United States Deputy Attorney General Edward E. Ayer (1841–1927), American antiquarian and benefactor Francis Ayer (1848–1923), American advertising businessman Frederick Ayer (1822–1918), American businessman Frederick Ayer Jr. (1915–1974), American government official
Harriet Hubbard Ayer (1849–1903), American cosmetics entrepreneur and journalist Hilal Tuba Tosun Ayer (born 1970), Turkish female referee James Cook Ayer (1818–1878), American patent medicine businessman Lewis Malone Ayer Jr. (1821–1895), Confederate politician Nat Ayer (1887–1952), British-American composer Richard S. Ayer (1829–1896), U.S. Representative from Virginia
See also Edward L. Ayers, American historian and educator Sir Henry Ayers (1821–1897), South Australian premier Ayers Rock, named for him (now Uluru) Ayre (surname) Eyre (surname)