Mackay is a Scottish surname and given name of Norman origin, derived from the place name Magh Cuil, meaning 'plain of Cul'. It was originally a habitational name for someone who lived in the parish of Macharioch, Argyllshire, Scotland. The name has been used as both a first and last name since medieval times.
The name Mackay experienced a gradual decline in popularity over time, with the highest number of births recorded in 1997 and 2005 at 12 each, and a consistent decrease thereafter until it leveled off around 6-8 births per year since 2018.