Since late December 2012, Canadian astronaut Chris Hadfield has been conducting experiments at the ISS as part of the international crew.
On Wednesday, he took control of the giant orbiting lab, becoming the first Canadian to command the ISS.
It also marked only the second time that someone other than an American or Russian has taken on the job.
Astronaut David Saint-Jacques says it`s a sign of confidence in Canada from the rest of the world.
The transfer of command from NASA astronaut Kevin Ford was marked by the ringing of a ceremonial bell.
Hadfield will head Expedition 35. It officially begins with the undocking of the Soyuz TMA-06M spacecraft on Thursday.
He will run the station along with five other crew members and will return to Earth in mid-May.
Since being in space, Hadfield has become a Twitter sensation, posting stunning pictures and commenting on his experiences so far.
"Good Morning, Earth!," he Tweeted Wednesday. "Time for 16 sunrises, a day of research work, and tonight Kevin hands me the spaceship's keys."
Later that day he wrote, "I've received a world of congratulations on newly commanding this spaceship. Very big moment in my life."
With files from The Canadian Press