Allyn is both a unisex given name and a surname. Notable people with the name include:

Given name

• Leigh-Allyn Baker (born 1972), American actress, director and voice artist
• Allyn L. Brown (1883–1973), American judge
• Allyn Capron (1846–1898), US Army captain
• Allyn K. Capron (1871–1898), first US Army officer to die in the Spanish–American War
• Allyn Condon (born 1974), English sprinter
• Allyn Cox (1896–1982), American painter
• Allyn Ferguson (1924–2010), American composer
• Allyn Joslyn (1901–1981), American stage, film and television actor
• Ruth Allyn Marcus (born 1958), American journalist and political commentator
• Allyn McKeen (1905–1978), American college football coach
• Allyn Ann McLerie (1926–2018), American dancer
• Francis Allyn Olmsted (1819–1844), American author
• Wayne Allyn Root (born 1961), American businessperson
• Allyn Rose (born 1988), American beauty pageant titleholder and model
• J. Allyn Rosser (born 1957), American poet
• Allyn Stout (1904–1974), American Major League baseball pitcher
• Allyn Vine (1914–1994), American physicist and oceanographer
• Allyn Abbott Young (1876–1929), American economist

Surname

• Arthur Allyn Jr. (1913–1985), American co-owner of the Chicago White Sox baseball team
• Daniel B. Allyn (born 1959), US Army general
• David Allyn (born 1969), American essayist
• Edna Allyn (1861–1927), American librarian
• Eunice Eloisae Gibbs Allyn (1847–1916), American writer
• Jerri Allyn (born 1954), American artist
• John Allyn (1917–1979), American co-owner of the Chicago White Sox baseball team
• Joseph P. Allyn (1833–1869), American judge and journalist
• Louis B. Allyn (1874–1940), American chemistry professor