Humphrey St John-Mildmay (1794–1853) was an English merchant banker and politician, a partner with Baring Brothers.
St John-Mildmay joined the Coldstream Guards and served as a captain in the Peninsular War. After marrying Anne Baring, daughter of Alexander Baring in 1823[1] he was offered a partnership in the family bank. They had one child, Humphrey Francis St John-Mildmay (1825–1866)
St John-Mildmay was also appointed a Director of the Bank of England.[2] He was Conservative MP for Southampton, Hampshire.[2] He spoke and voted against the Slave Trade Suppression Bill in 1843.[3]
He lived at Mount Clare, Roehampton from 1830–32.[4]