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