William Oscar Jules Moser was born in 1927 in Winnipeg, MB, Canada. He married Beryl Rita Pearlman in 1953 and together they have 3 children: Marla, Lionel and Paula.

Moser's education began at the University of Manitoba where he obtained a Bachelor of Science (honours) degree (1949), and continued to the University of Minnesota where he was granted his Master's in 1951. Under the advisory of Donald Coxeter, Moser completed his PhD in mathematics at the University of Toronto in 1957. Moser's academic career began at the University of Saskatchewan where he was an Associate Professor from 1956-1960. From there, he moved to the University of Manitoba where he was also an Associate Professor from 1959-1964. His final placement was at McGill University in 1964 (professor from 1966 on) where he stayed until his retirement in 1997. During the years, Dr. Moser and his family spent time in England and Paris while on sabbatical leaves from McGill, but Montreal remains their home. Some of his close professional friendships include: Donald Coxeter, Paul Erdos, Sy Schuster, etc. His most famous publication was "Generators and relations for discrete groups, 1957" with Donald Coxeter. This work has garnered attention for its longevity and importance as it is currently in its 8th edition. Dr. Moser is still publishing books in the field of mathematics with fellow mathematicians. It is important to note that Prof. Moser's main contribution to the mathematical world is within the field of geometry.