He was the son of John Morison of Saughtonhall (1558–1615), a burgess and treasurer of the city of Edinburgh, and his wife, Katherine Preston, daughter of John Preston, Lord President of the Court of Session. He was born in 1579 probably in Saughton Hall, just west of Edinburgh.
His sister Catherine, married William Scott, Lord Clerkington.
Saughton Hall stood in 98 acres of ground and was demolished by Edinburgh Council in 1952 to make way for housing.
- The Buildings of Scotland: Lothian:Prestongrange, Colin McWilliam
- An Historical Account of the Senators of the College of Justice