Although a Conservative, he ran as a Liberal in a November 1887 by-election resulting from his election at the general election the previous March having been declared void, and thus sat as such from November 1887 to March 1891.
He was born in North East Margaree, Nova Scotia, the son of Laughlin McDonald, a Scottish immigrant.
McDonald was called to the Nova Scotia bar in 1877.
He represented Victoria County in the Nova Scotia House of Assembly from 1882 to 1886 as a Conservative.
McDonald was also a trustee for the Baddeck Academy and municipal clerk for Victoria.