Nathan Fellowes Dupuis was born on April 13, 1836, in Portland Township, Frontenac County, Upper Canada.

He was a science professor. He was apprenticed at the age of 14 to a Kingston clockmaker, William Smith, after building a clock from materials found on the family farm. He practised the art of clock-making for a few years while pursuing studies in math and astronomy. He taught public school for six years and in 1863, he entered Queen's University where he was given the post of Observer in the university observatory. He graduated in 1866 and became a Queen's librarian. Dupuis began his teaching career as Professor of Chemistry and Natural History in 1868. He was appointed Professor of Mathematics and Chemistry in 1880 and in 1881, he became Professor of Pure Mathematics. He was a founder of the Faculty of Practical Science at Queen's and was made its first Dean in 1894, the post he retained until his retirement in 1911. He was a charter member of the Royal Society of Canada in 1882 and president of his section in 1896. He published several books, e.g., “Elements of Geometrical Optics” (1868) and “Elementary Synthetic Geometry of the Point, Line and Circle in the Plane” (1889). He was also a painter and loved to play the violin.

In 1860, he married Amelia Anne McGinnis (1844–1905) and in 1906, he remarried Mae Gordon Thompson (1868-1943). He died on July 20, 1917, in Long Beach, California.