Ioan Mackenzie James FRS (born 23 May 1928) is a British mathematician working in the field of topology, particularly in homotopy theory.
James was born in Croydon, Surrey, England,[2] and was educated at St Paul's School, London and Queen's College, Oxford.
from the University of Oxford for his thesis entitled Some problems in algebraic topology, written under the direction of J. H. C. Whitehead.
In 1957 he was appointed reader in pure mathematics, a post which he held until 1969.
From 1959 until 1969 he was a senior research fellow at St John's College.