William Drummond, 1st Viscount of Strathallan, Lord Drummond of Cromlix (1617? – 1688), was a Scottish soldier and politician. He served as a Commissioner for Perthshire in the parliaments of 1669–74, 1681–2 and 1685–6, and at the Convention of Estates of 1678. Drummond was a Royalist general and held a command in the Engagement of 1648. He served in Ireland under the Marquis of Ormonde and was taken prisoner at theBattle of Worcester, but escaped. He served as Lieutenant-General in the Muscovite army. After the Restoration he was appointed Major-General of the forces in Scotland (1666).