Isaac Ewer (died c.1650) was an English soldier and one of the Regicides of King Charles I of England.
[citation needed] He was likely born in Essex; in his last will and testament, he describes himself as of Hatfield Broad Oak and before the Civil War was "but a serving-man".
[1] It was Ewer who presented to the House of Commons, on 20 November 1648, the declaration of the army in which they insisted on Charles I being speedily brought to justice.
[2] Ten days later Ewer was given the custody of the king at Hurst Castle, of which he was made governor.
He took part in the storming of Drogheda, 10 September, where most of his officers were severely wounded, was at Clonmel 9 May 1650, and during June and August of the same year assisted Ireton in the reduction of Waterford.