The Iron Ring is a ring worn by many Canadian-trained engineers, as a symbol and reminder of the obligations and ethics associated with their profession. The ring is presented to engineering graduates in a private ceremony known as the Ritual of the Calling of an Engineer. The concept of the ritual and the rings originated from H. E. T. Haultain in 1922, with assistance from Rudyard Kipling, who crafted the ritual at Haultain's request.

Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. The word engineer is derived from the Latin words ingeniare and ingenium ("cleverness"). The foundational qualifications of a licensed professional engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professional practice and passage of engineering board examinations.