Charles Gordon Hewitt (February 23, 1885 – February 29, 1920) was a Canadian economic entomologist and pioneer of conservation biology. He was appointed dominion entomologist of Canada in 1909. He helped pass the Destructive Insect and Pest Act in 1910, and implemented significant changes in the Department of Agriculture. He published several books on the subjects of biology and entomology, and helped to further the 1916 treaty between Canada and the United States for the protection of migratory birds.