Henry Danby Seymour (1 July 1820 – 4 August 1877) was a British gentleman and Liberal Party politician. Seymour was the eldest son of Henry Seymour and wife Jane Hopkinson. Alfred Seymour was his brother. A member of the Liberal Party, he sat as Member of Parliament (MP) for Poole from 1850 to 1868 and served as Joint Secretary to the Board of Control, the body which oversaw the activities of the East India Company, from 1855 until the Company's abolition in 1858. In November 1876 he was elected to the London School Board. He did not marry and died without issue.