Sir Henry Cosmo Orme Bonsor, 1st Baronet, DL (2 September 1848 – 4 December 1929) was an English brewer and businessman and a Conservative politician who sat in the House of Commons from 1885 to 1900.
Bonsor was the son of Joseph Bonsor of Polesden Lacey. He was educated at Eton and with his father and brother became a partner in the brewing firm of Combe & Co. He was a director of the Bank of England, and a Governor of Guy's Hospital.
In 1885 Bonsor was elected M.P. for Wimbledon and held the seat until 1900. Also in 1885, Bonsor purchased the estate of Kingswood Warren, Surrey from Sir John Cradock Hartopp and lived there until 1906 when he put it on the market because of the rising cost of maintenance.
In 1897 Bonsor became chairman of the South Eastern Railway and in the same year the railway line was extended from Purley railway station to Kingswood railway station. In 1898 he organised the brewery amalgamation to form Watney Combe & Reid, of which he remained chairman until 1928. In 1899 he arranged the amalgamation of the South Eastern Railway and the London Chatham & Dover Railway, and became chairman of the managing committee. In the same year he formed a private syndicate to extend the Tattenham Corner Line from Kingswood to Tattenham Corner railway station to take the racegoing traffic to Epsom Downs Racecourse. A train named in his honour formerly ran as part of the Southern services to London Bridge. The train stock was of Class 456.