Edward Southwell, Sr. (4 September 1671 – 4 December 1730) was an Anglo-Irish lawyer and politician.
He was the second but only surviving son of Sir Robert Southwell of Kings Weston, near Bristol and educated at Kensington School, Lincoln's Inn (1686) and Merton College, Oxford (1687).
He served in a number of high public offices including Chief Prothonotary of the Common Pleas in Ireland (1692–1700), clerk of the Privy Council (1693 to death), judge of the Admiralty court and vice-admiral of Munster (1699 to death). He was several times joint commissioner of the Privy Seal (1701–1702, 1715 and 1716). He was elected a Fellow of the Royal Society in 1692 and twice served on their council.
He sat in the Irish House of Commons for Kinsale from 1692 to 1699, for Dublin University from 1703 to 1713 and then again for Kinsale from 1713 to his death.
In 1702 Southwell succeeded his father as Principal Secretary of State (Ireland) and was appointed to the Privy Council of Ireland the same year. Both appointments were for life.
He sat in the House of Commons of England and the House of Commons of Great Britain between 1702 and 1715 as MP for Rye, Tregony and Preston.