Ian Nicholas Stewart FRS (born 24 September 1945) is a professor of mathematics at the University of Warwick, England, and a widely known popular-science and science-fiction writer. He is the first recipient of the Christopher Zeeman Medal, awarded jointly by the LMS and the IMA for his work on promoting mathematics.
Stewart was born in 1945 in England. While in the sixth form at school, Stewart came to the attention of the mathematics teacher. The teacher had Stewart sit mock A-level examinations without any preparation along with the upper-sixth students; Stewart placed first in the examination. This teacher arranged for Stewart to be admitted to Cambridge on a scholarship to Churchill College, where he obtained a BA in mathematics. Stewart then went to the University of Warwick for his doctorate, on completion of which in 1969 he was offered an academic position at Warwick, where he presently professes mathematics. He is well known for his popular expositions of mathematics and his contributions to catastrophe theory.
While at Warwick he edited the mathematical magazine Manifold. He also wrote a column called "Mathematical Recreations" for Scientific American magazine for several years.
Stewart has held visiting academic positions in Germany (1974), New Zealand (1976), and the U.S. (University of Connecticut 1977–78, University of Houston 1983–84).
Stewart married his wife, Avril, in 1970. They met at a party at a house Avril was renting while she trained as a nurse. They have two sons. He lists his recreations as science fiction, painting, guitar, keeping fish, geology, Egyptology and snorkeling.
In 1995 Stewart received the Michael Faraday Medal and in 1997 he gave the Royal Institution Christmas Lecture on The Magical Maze. He was elected as a Fellow of the Royal Society in 2001.