This paper explores the entangled histories of Indigenous protection, medical research, ethnology and geography in mid-nineteenth century London. The Quaker physician, Dr Thomas Hodgkin, was both a passionate advocate of the rights of Indigenous people in Britain’s empire and a noted medical researcher: he co-founded the Aborigines’ Protection Society (APS) and the Ethnological Society of London (ESL); whilst also serving the Royal Geographical Society; the Provincial Medical and Chirurgical Society (forerunner of the British Medical Association); and the British Association for the Advancement of Science. Hodgkin routinely transferred ideas and practices from one field to inform his work in others, but was as concerned with re-deploying personal contacts and institutional structures across arenas. This paper explores how – in an era when scientific disciplines were being actively demarcated, and the markers of professional status keenly sought – intersecting scientific, religious and humanitarian networks were used to promote indigenous protection. By foregrounding the humanitarian imperative to protect indigenous rights, it also challenges the accepted account of the formation of the ESL as a ‘break’ by scientists from the humanitarians of the APS.