Sir Henry Seymour, 1st Baronet MP (20 October 1674 – April 1714) was a British gentleman and politician.
He was a Member of Parliament for East Looe from 1699 to 1710. He was created 1st Baronet Seymour, of Langley, on 4 July 1681. He died in London in 1714.
He bought Langley Park in 1669, and it was sold in 1714 to Samuel Masham, 1st Baron Masham.
He was the second son of Henry Seymour, of Langley, Buckinghamshire (1612 – 9 March 1686), Groom of the Bedchamber, and second wife Ursula Austen, daughter of Sir Robert Austen, 1st Baronet, and wife, and widow of George Stawale, and paternal grandson of Sir Edward Seymour, 2nd Baronet, and wife Dorothy Killegrew.
He died unmarried and without issue.