Henry Nicholas Ridley CMG (1911), MA (Oxon), FRS, FLS, F.R.H.S. (10 December 1855 – 24 October 1956) was an English botanist and geologist.Born at West Harling Hall, Norfolk, England. Ridley was the first Scientific Director of the Singapore Botanic Gardens from 1888 to 1911.Ridley spent many years promoting rubber as a commercial product, which he was known for being passionate; therefore, he was nicknamed "Mad Ridley".