Ross Honsberger (1929–2016[1]) was a Canadian mathematician and author on recreational mathematics.
Honsberger studied mathematics at the University of Toronto, with a bachelor's degree, and then worked for ten years as a teacher in Toronto, before continuing his studies at the University of Waterloo (master's degree).
He developed education courses, for example, on combinatorial geometry, frequently held lectures for students and math teachers, and was editor of the Ontario Secondary School Mathematics Bulletin.
He wrote numerous books on elementary mathematics (geometry, number theory, combinatorics, probability theory), and recreational mathematics (often at the Mathematical Association of America, MAA), with him in his own words using the book by Hans Rademacher and Otto Toeplitz of numbers and figures as a model.
Frequent were his expositions of problems at the International Mathematical Olympiads and other competitions.