William Maxwell Cowan (27 September 1931 – 30 June 2002) was a South African neuroscientist known for his work on developmental plasticity and neural connectivity.

In the 1920s, Cowan's family, who previously worked in the shipbuilding industry in Scotland, emigrated to South Africa to look for mining jobs in Transvaal Province after the British government closed many of their shipyards in Glasgow during a peacetime downturn.

However, when the firm discovered how young he was, they asked Cowan's family to enroll him at University of the Witwatersrand for at least one year, where he would study prelaw with the goal of specialising in real estate law.

[5][6] Cowan's interest in a legal career that first year soon waned, and he became more aware and troubled by the inequality between whites and blacks in South African society.

In 1953, at the recommendation of anthropologist Raymond Dart, Cowan went on to Hertford College, Oxford, to study neuroanatomy and perform doctoral research under Wilfrid Le Gros Clark, earning his DPhil (1956) and his BM BCh (1958).

"[3] Cowan became director of developmental neurobiology at the Salk Institute for Biological Studies from 1980 to 1986, until he returned to Washington University as provost and executive vice-chancellor.