Here are some facts about him:
Born Aug. 29, 1959, in Sarnia, Ont., and raised on a corn farm in Milton, Ont.
Married on Dec. 23, 1981, to Helene Hadfield, with three adult children: Kristin, Evan and Kyle.
Becomes interested in flying from a young age and, as an air cadet, wins a glider-pilot scholarship at 15.
Joins the Canadian Forces in May 1978 and goes on to fly CF-18s for NORAD, the North American Aerospace Command.
In 1992, is selected to become one of four new Canadian astronauts from a field of 5,330 applicants.
In 1995, becomes the only Canadian to ever board the Russian Space Station. Serves as a mission specialist on NASA's second shuttle mission to dock with the Mir station.
In 2001, is mission specialist as U.S. Space Shuttle Endeavour delivers and installs Canadarm2 on International Space Station. During the 11-day flight Hadfield performs two space walks, making him the first Canadian to float freely in space.
In 2010, is commander of NEEMO-14, a NASA underseas facility off the coast of Florida. It uses the ocean floor to simulate exploration missions to the surface of asteroids, the moon and Mars.
On Dec. 19, 2012, launches aboard a Russian Soyuz for a long-duration visit to the International Space Station. Is involved in more than 100 science experiments. Draws more than 750,000 social-media followers as he posts hundreds of pictures of Earth.
On March 13, 2013, becomes first Canadian to command the space station during the last part of his five-month stay.
Hadfield is due to return to Earth on Monday, May 13, aboard a Russian space capsule and land in Kazakhstan around 10:30 p.m. ET.