Donald, Lord of the Isles (Gaelic: Dómhnall; died 1423), is the son and successor of John of Islay, Lord of the Isles and chief of Clan Donald.

The Lordship of the Isles is based in and around the Scottish west-coast island of Islay, but under Donald's father had come to include many of the other islands off the west coast of Scotland, as well as Morvern, Garmoran, Lochaber, Kintyre and Knapdale on the mainland.

Donald is the grandson of King Robert II of Scotland and first cousin of King Robert III; he takes pride in his royal blood, even adopting the royal tressure to surround his coat of arms.

While it is customary to portray the Lords of the Isles as divorced from the mainstream of Scottish political life, and as representatives of a brand of lordship distinct from the rest of Scotland, this view obscures the fact that Donald is only one of many magnates who hold large lordships with little interference from the crown in late fourteenth and early fifteenth century Scotland.

The Douglas kindred of southern Scotland and the Albany Stewarts have similar roles as Donald.