James Mario Matra (1746 – 29 March 1806), sailor and diplomat, was an American-born midshipman on the voyage by James Cook to Botany Bay in 1770. He was the first person of Corsican heritage to visit the future nation of Australia.
His father James was a member of a prominent Corsican family who had migrated to Dublin, Ireland in the early 1730s, where he studied medicine and changed his surname from Matra to Magra. He moved to New York City, United States, where his son James Mario Magra was born in 1746. James Mario later settled in England. Australian historians remember him for his misbehaviour aboard James Cook's Endeavour on its voyage of exploration to New Holland in 1768–70. Magra was suspected of snipping of the earlobes of Cook's drunken and alcoholic clerk after stripping him naked while he was drunk. During this voyage, Magra became acquainted with Sir Joseph Banks, and their friendship lasted until his death. Circumstantial evidence has identified Magra as the anonymous author of A Journal of a Voyage Round the World, which appeared two months after his return to England in 1771, and which offered some details of Cook's voyage not found in other accounts.
In 1775, Magra petitioned the King to have his surname revert to its original form Matra, in order to claim a Corsican inheritance.
Matra was the author of the "Proposal for Establishing a Settlement in New South Wales" put forward in 1783, which the immediate forerunner of the official and semi-official "plans" was resulting in the foundation of the first Australian colony.
In a letter to the British Government in 1783, Matra discussed the potential commercial benefits to Britain of a settlement. He recommended that Britain should send American loyalists and/or convicts to settle at Botany Bay in New South Wales. He looked forward to Australia as an asylum for "those unfortunate loyalists to whom Great Britain was bound by every tie of honour and gratitude and with visions, perhaps, of a reproduction of the life of the planters of Virginia and Carolina". He pushed the latter plan partly because he had aspirations to become the first Governor of the new penal colony.