Sir Henry Seymour, 1st Baronet (20 October 1674 – April 1714), of Langley, Buckinghamshire, was an English landowner and Tory politician who sat in the English and British House of Commons from 1699 to 1713. Seymour died unmarried and without issue in London in April 1714. Langley Park, Buckinghamshire was sold in 1714 to Samuel Masham, 1st Baron Masham.