Joseph Williamson, English politician, Secretary of State for the Northern Department (born 1633)

Sir Joseph Williamson, PRS was an English civil servant, diplomat and politician who sat in the House of Commons of England variously between 1665 and 1701 and in the Irish House of Commons between 1692 and 1699. He was Secretary of State for the Northern Department from 1674 to 1679.

The secretary of state for the Northern Department was a position in the Cabinet of the government of Great Britain up to 1782. Following this, the Northern Department became the Foreign Office, and the position evolved into the foreign secretary.