A feminine form of Alan; variant spelling of Alana. Also possibly derived from Elaine (Old French) "bright, shining" or Helen (Greek) "light." The spelling Alannah is possibly influenced by names of Hebrew origin such as Hannah and Susannah and by the Anglo-Irish term of endearment "alanna", "alannah" "alanah" or "a leanbh" meaning "O child.".
From the Celtic/Gaelic, Alanna possibly means "Fair". It can also be derived from the combination of the father`s name Allan, with the mother`s name Donna, to form Alanna.