Tullynakill (from Irish Tulaigh na Cille, meaning 'knoll of the church')[1] is a civil parish and townland (of 317 acres) in County Down, Northern Ireland.

It is situated in the historic barony of Castlereagh Lower.

[2] The name Tullynakill appears in the 1615 Terrier of church property and on the Raven maps of c.1625.

An inquisition on the bishop's land was taken at Tullomkill in 1617, and in 1659 Tollenekill was the parish and Tolinkill the townland.

[1] Antiquarian William Reeves noted in the mid-19th century the ruins of a 17th-century church next to the one then in use in Tullynakill townland.