The 32-year-old midfielder, who had been at the Giuseppe Meazza for five seasons, has signed for the remainder of the season with the option of another two years when the current deal expires.
The former Paris Saint Germain man has found himself out-of-favour with The Neroazzurri and he had been told he was free to leave as was not part of Hector Cuper's plans.
Although the transfer window has closed in Italy Cauet has got round this by buying out the remainder of his Inter contract.
Cauet admitted he needed to leave Inter for first team football and he was looking forward to the challenge at Torino.
"Here is a beautiful adventure which is completed," said Cauet. "From now on another begins and I can ressurect my career.
"The trainer (Cuper) has other options, which I respect and he was always honest on his decisions.
"From there to go to a club which will enable me to play is better for me. I have an opportunity to continue my career but it will not be easy.
Cauet faces a baptism of fire for his debut with the Turin derby against Juventus and the Frenchman insists he is ready for the challenge.
"There is nothing like a good derby to get you in the mood and I am ready," declared Cauet.
