His father, Lauchlan Maclean, 2nd Laird of Brolas, died at an early age.
Donald entered the army and served for some time as lieutenant during the reign of Queen Anne; but in the attempt made by her brother for the recovery of the crown of his ancestors, in 1715, Maclean of Brolass served as lieutenant-colonel under his cousin, Sir John Maclean, 4th Baronet, at the Battle of Sheriffmuir, where he received two severe wounds on the head from a trooper's saber.
[1] He was married to Isabella, daughter of Allan MacLean, 10th Laird of Ardgour.
They had the following children: Donald also had a natural, or illegitimate son, called Gillian Maclean, who became a lieutenant in Guernsey, was married, and had issue.
[1] This article incorporates text from A history of the clan Mac Lean from its first settlement at Duard Castle, in the Isle of Mull, to the present period, by John Patterson MacLean, a publication from 1889, now in the public domain in the United States.