Originally from Achnacarry in Lochaber, Donald graduated from the University of Oxford. He then worked at the Center for Strategic and International Studies in Washington DC before returning to the UK to study law. He qualified as an Advocate at the Scottish Bar in 2005 and practised across Scotland. He was appointed a Standing Junior Counsel to the Scottish Government 2009-2016.
He was elected a Member of the Scottish Parliament for the Highlands and Islands Region at the Scottish Parliamentary elections in May 2016 and 2021.
In Parliament, he sits on the Constitution, Europe, External Affairs and Culture Committee.