|Born||28 December 1782
|Died||26 July 1818
Born in Beccles, Suffolk, he learned surgery in Edinburgh and received a diploma in 1807. 1808-1815 he worked as a naval surgeon for the Royal Navy, including two trips to Australia (1809 with HMS Hindostan; and in 1815 with HMS Northumberland). After 1815 he unsuccessfully tried to work as surgeon in Sydney, and upon his return trip to England he was stranded in Batavia. In 1818 he worked with Sir Stamford Raffles in Sumatra, where he died.
The largest flowering plant, Rafflesia arnoldii, was discovered by an Indonesian guide working for him and later named in Arnold's honour.