James William McBain (March 22, 1882 – March 12, 1953) was a Canadian chemist.
He gained an MA at Toronto University and a DSC at Heidelberg University.
He carried out pioneering work in the area of micelles at the University of Bristol. As early as 1913 he postulated the existence of “colloidal ions”, now known as micelles, to explain the good electrolytic conductivity of sodium palmitate solutions. He was elected a Fellow of the Royal Society in May 1923 [1] He won their Davy Medal in 1939.