Henry Parker (1604–1652) was an English barrister and political writer in the Parliamentarian cause.
He was a major figure as a propagandist and pamphleteer, "the most influential writer to defend the parliamentary cause in the 1640s".[1] He provided the "ideological ballast for resistance", according to Geoffrey Robertson.[2] He operated on behalf of the "coalition" of aristocrats and gentry who took over in the Long Parliament.[3] He formulated a theory of sovereignty for the side of Parliament in its conflict with Charles I of England, based on the consent of the people.[4]