Ivan Morton Niven (October 25, 1915 – May 9, 1999) was a Canadian-American number theorist best remembered for his work on Waring's problem.

He worked for many years as a professor at the University of Oregon, and was president of the Mathematical Association of America.

He was president of the Mathematical Association of America (MAA) from 1983 to 1984.

Niven completed the solution of most of Waring's problem in 1944.

[3] This problem, based on a 1770 conjecture by Edward Waring, consists of finding the smallest number

[5] Niven received the University of Oregon's Charles E. Johnson Award in 1981.

He received the MAA Distinguished Service Award[6] in 1989.