Alfred Grandidier was a French naturalist and explorer.
From a very wealthy family, at the age of 20, he and his brother, Ernest Grandidier, undertook a voyage around the world. At first they were led by the astronomer and physicist Pierre Jules César Janssen, but when Janssen fell sick and had to return to France after about six months, the brothers continued the journey.
They visited South America in 1858 and 1859 and in particular the Andes, Peru, Chile, Bolivia, Argentina and Brazil. During this voyage they gathered a significant collection of specimens which were analyzed, in 1860, by Ernest.
The two brothers parted ways after this. Ernest Grandidier went to China and collected a vast number of specimens which are now in the Louvre and the Guimet museum. Alfred travelled to India, reaching it in 1863. He had intended to explore the high plateau of Tibet, but was prevented by a severe attack of fever.
Grandidier travelled to Zanzibar to recuperate, remaining some time and making important collections and publishing an account of his findings. He then visited the island of Réunion and in 1865 made his first visit to Madagascar.