The Great Tit is sometimes listed as one and the same bird as the Cinereous Tit, which in turn belongs to a group of tits that consists of several populations that were earlier treated as subspecies of the Great Tit (fig.).

It is ashy grey, with white undersides. However, the Great Tit is sometimes described as greenish-backed with a yellowish underside, a description also used for the Green-backed Tit.