Alastair Mackenzie is a Scottish actor. Alastair Mackenzie was educated at Westbourne House School and Glenalmond College in Perthshire.

Alastair Mackenzie left home at the age of 18 and moved to London. Though best known as playing the young laird Archie MacDonald in the BBC drama Monarch of the Glen, he also has some theatre and film credits to his name.

Alastair Mackenzie lives in Islington with his wife, Scottish actress Susan Vidler, with whom he has two children: a daughter Martha born in February 2000 and a son Freddy born 2004.