Sir William Montagu (c.1618 – 26 August 1706) was an English judge and politician who sat in the House of Commons variously between 1640 and 1695.
He was educated at Oundle School and admitted to Sidney Sussex College, Cambridge on 15 April 1632.
[1] In 1660, Montagu was elected MP for Cambridge University in the Convention Parliament.
He sat on the Bench at several of the Popish Plot trials, and appeared just as credulous as the other judges about the testimony of Oates and the other informers; but at the trial of Titus Oates for perjury in 1685, under pressure from Lord Chief Justice Jeffreys, he claimed that he had never thought Oates a credible witness.
Montagu was removed from the bench in 1686 because he refused to give an unqualified opinion in favour of the Royal Prerogative of dispensing individuals from the provisions of a statute, which was a crucial part of James II's policy of toleration for Roman Catholics.