Sir Alexander de Cokburne (b. c1310, d. c1370) was born into a mid-level landowning family in the Scottish Borders.
For the five centuries following Sir Alexander, the Cockburn family was, through its significant landholdings and political connections, an influential force in Scottish affairs.
Sir Alexander's parentage is unclear from the surviving record; however, his marriages to two prominent heiresses suggest that he was from a well-known branch of the Cockburn family.
Sir Alexander's second marriage to the heiress Maria de Monfode added the barony of Skirling (in Peeblesshire).
Other branches of the family acquired estates at Ormiston and Clerkington (just southwest of Haddington) in East Lothian.