MacLean, also spelt McLean, is a Scottish Gaelic surname (Mac Gille Eathain, or, Mac Giolla Eóin in Irish Gaelic), Eóin being a Gaelic form of Johannes (John).

The clan surname is an Anglicisation of the Scottish Gaelic "Mac Gille Eathain", a patronymic meaning "son of Gillean".

Gillean means "the Servant of [Saint] John [the Baptist]"),[1] named for Gilleathain na Tuaidh, known as "Gillian of the Battleaxe", a famous 5th century warrior.

[2] Eachan Reaganach and his brother Lachlan were descended from Gilleathain na Tuaidh, and are the progenitors of the clan.

[2] Duart Castle is the seat of Clan MacLean.