He was born in St. Andrews in Upper Canada in 1793, the son of Neil McLean.

He served as a lieutenant in the local militia during the War of 1812.

He was named justice of the peace in the Eastern District in 1832.

In 1837, McLean was elected in a by-election to represent his home county, Stormont, in the Legislative Assembly of Upper Canada.

[1] The by-election was triggered when his brother Archibald, who was the member for Stormont, resigned the seat to accept an appointment as judge.