The name Lennon can refer to one of several individuals or groups: Anglicized from Irish O ó (“leannain leannáin Descendant (of)”) lover leannan LEANNáN And (“from o ó (Lionain)”). 1  Lionáin Descendant (of–blackbird), lonan, lonán, john lennon 1940 1980 singer musician poet and Songwriter Famous.  as a member of the beatles John Lennon (1940–1980), singer, musician, poet and songwriter famous as a member of The Beatles. 2  Cynthia Lennon (1939–2015), John Lennon's first wife (born Cynthia Powell). 3  Julian Lennon (born 1963), John Lennon's first son, with Cynthia Powell. 4  Sean Lennon (born 1975), John Lennon's second son, with Yoko Ono.