The Third Protectorate Parliament sat for one session, from 27 January 1659 until 22 April 1659, with Chaloner Chute and Thomas Bampfylde as the Speakers of the House of Commons. It was a bicameral Parliament, with an Upper House having a power of veto over the Commons.

Sir Arthur Haselrig, 2nd Baronet was a leader of the Parliamentary opposition to Charles I and one of the Five Members whose attempted arrest sparked the 1642–1646 First English Civil War. He held various military and political posts during the 1639–1651 Wars of the Three Kingdoms but became an opponent of Oliver Cromwell during the Protectorate. In 1660, his actions inadvertently helped restore Charles II to the throne; unlike many senior Parliamentary leaders, his life was spared but he was confined to the Tower of London, where he died on 7 January 1661.