Oleg Kotov and Sergei Ryazansky took the unlit version of the torch through the hatch of the International Space Station.
The torch will spend up to six hours in open space.
The Olympic torch has been carried into space twice before – in 1996 and 2000 – but it has never left a spaceship. It is not being lit aboard the space station as this would consume oxygen and pose a risk to the crew.
The Sochi torch will then be returned to Earth and used to light the Olympic cauldron in February next year.
The trip to the space station is all part of elaborate preparations for Russia’s first Olympics since the Soviet era. The games are the most expensive Olympics so far, costing around $50bn (£31bn; 1,620bn roubles).