The Ethnological Society of London (ESL) was a learned society founded in 1843 as an offshoot of the Aborigines' Protection Society (APS). The meaning of ethnology as a discipline was not then fixed: approaches and attitudes to it changed over its lifetime, with the rise of a more scientific approach to human diversity. Over three decades the ESL had a chequered existence, with periods of low activity and a major schism contributing to a patchy continuity of its meetings and publications. It provided a forum for discussion of what would now be classed as pioneering scientific anthropology from the changing perspectives of the period, though also with wider geographical, archaeological and linguistic interests.
In 1871 the ESL became part of what now is the Royal Anthropological Institute of Great Britain and Ireland, merging back with the breakaway rival group the Anthropological Society of London.