Francis Buchanan FRS FRSE FLS, later known as Francis Hamilton but often referred to as Francis Buchanan-Hamilton, was a Scottish physician who made significant contributions as a geographer, zoologist, and botanist while living in India. He did not assume the name of Hamilton until three years after his retirement from India.
The standard botanical author abbreviation Buch.-Ham. is applied to plants and animals he described, though today the form "Hamilton, 1822" is more usually seen in ichthyology and is preferred by Fishbase.