Jonathan is now officially an Inter player after his contract was deposited with the Lega Serie A on Friday.
The Brazilian joined the Nerazzurri at their pre-season training base earlier this week and his transfer has now been confirmed.
The right-back, who has arrived from Santos for an undisclosed fee, has signed a deal until June 2015.
Jonathan is currently working on a personal training programme at Pinzolo after picking up a muscle strain in his last match with his previous club.
The stopper, full name Jonathan Cicero Moreira, is 25-years-old and only joined Santos from Cruzeiro in a part-ownership deal in December 2010.