The 26-year-old striker penned a two-year extension to his Inter contract but PSG has a 65 million euro option to buy the Argentine.
The move will interrupt a turbulent six-year spell at Inter- Milan for the Argentine, who has fallen out with fans along on the way.
He also provided fodder for gossip columns thanks to his marriage to Wanda Nara, a media personality who also acts as his agent.
Inter said that as part of the deal it had also extended Icadi’s contract by two years until 2022.
The move was to avoid the possibility of him leaving as a free agent next year.
“The Argentine forward has signed for the French club on an initial year-long loan with the option to make the deal permanent at the end of this period,” said an Inter statement.
However, Icardi while speaking on the new deal with the French club promised to give everything to help his new team go as far as possible in all competitions.”