This Atlas of the hair of Canadian mammals provides an introductory text to trichology, i.e., the study of hairs, that may be useful for teaching purposes on evolution and general biology in mammals integuments. It includes two major sections. The first section covers a brief historical review of trichology and a broader taxonomical scope that integrates processes of hair evolution and development, morphological aspects, and utility of trichomorphological approaches in taxonomy, systematics, and mammal field inventories. The second section is entirely dedicated to the hairs of Canadian mammals. It provides detailed descriptions of the pelages and hairs for each genus and an identification key based on macro- and microscopic structures of dorsal guard hairs. This Atlas was designed to be useful for experts in taxonomy, but also for students, citizen scientists, and simple amateurs who wish to know more about hair and contribute to the advancement of mammalogy in Canada. By providing new and highly detailed information on hair morphology of all Canadian mammals, which is at heart of this project, it is also an invaluable tool for completing comprehensive field inventories efficiently and ethically during punctual or long-term monitoring programs.