Hadfield commanded Expedition 35 mission and produced a number of viral YouTube videos and gained over a million Twitter followers while in orbit.
Hadfield began his career as an air cadet, progressed to military flying for entities including NORAD, and then became an astronaut in 1992 going to space a total of three times.
He was the only Canadian to visit the Russian space station Mir in 1995, the first Canadian to perform a spacewalk when he installed Canadarm2 onto the ISS in 2001.
The 53-year-old said he doesn't want to stand in the way of younger astronauts waiting for flights, especially since Canada won't get to send another person to the ISS until at least 2016.
"I didn't say I don't want to do this anymore, but every one of us is going to retire," Hadfield said during a CSA press conference.
"I'm not sure the fat lady has sung," Hadfield said. He said he would be surprised if he could fly with the CSA again, adding that commercial spaceflight is a more likely possibility.
Hadfield's expedition made some tricky repairs while setting a record for science experiment productivity. Hadfield recorded more than 140 educational videos, took 45,000 pictures and conducted several press conferences and school chats.
Expedition 35 "included millions of people around the world," Hadfield said. "We as a combined force reached a level of public involvement and public interest which was unprecedented."