William Drummond, 1st Viscount Strathallan

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 the Battle 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).

Drummond was imprisoned for 12 months in Dumbarton Castle. He served as General of the Ordnance (1684), general of the forces in Scotland, and was a Lord of the Treasury on the accession of James VII.