He was the oldest son of Alexander Malet (1704–1775), a rector at Combe Florey in Somerset, and his wife Ann.
He served in the East India Company and in 1785 was appointed Resident to the court of the Peshwas of Mahratta, subsequently building a house in a splendid park outside the town of Poona.
This treaty was signed with difficulty, as Tipu also sought to forge alliances with the Maratha Peshwas.
He continued to take an interest in India and influenced Thomas Daniell to publish Wales's paintings of the caves at Ellora, apart from writing about them.
In 1798 He left Bibi Jahanara Khan in Pune and her three children later moved to England after being baptized as Christians.