The Russian-built capsule docked with the space station 418 kilometers (260 miles) above the Earth, after a journey lasting five hours and 48 minutes.
NASA said that Italian air force captain Samantha Cristoforetti, along with Russian cosmonaut Anton Shkaplerov and American astronaut Terry Virts, arrived at the orbiting space lab at 0249 UTC on Monday.
"A new vehicle has arrived. The Soyuz is confirmed as attached properly," high above the Pacific Ocean, NASA television said.
NASA tweeted a photograph of the Soyuz immediately before it made contact with the ISS.
The three, who took off for the International Space Station (ISS) from a launch site in Kazakhstan, are set to stay in space until May 2015. They brought with them provisions including nearly a kilogram of caviar and an espresso machine.
The new astronauts join three others, including Russian Elena Serova. Cristoforetti's arrival means that it is the second time in the station's 16-year history that two women have been aboard on long-term missions.
'I have done nothing special'
Cristoforetti, 37, deflected questions about becoming Italy's first female astronaut during a prelaunch press conference from Kazakhstan on Saturday.
"I have done nothing special to be the first Italian woman to fly to space. I just wanted to fly to space and I happen to be the first," said Cristoforetti while speaking in Russian.
The new crew's schedule includes three spacewalks to prepare the station for a new fleet of US commercial "taxi" spacecraft that are due to begin flying crew to the station in late 2017.
The ISS has been short-staffed since November 9. That is when Russian cosmonaut Maxim Suraev, ESA astronaut Alexander Gerst of Germany and NASA's Reid Wiseman returned home.
They had been in orbit on the station, which serves as a laboratory operated by a partnership of 15 nations, for five-and-a-half months.
rc/av (AP, AFP)