The 27-year-old ended the season on a similar agreement with Napoli, but the Portugal international will now move to the San Siro for the upcoming campaign.
An Inter statement read: "Rolando Jorge Pires da Fonseca, better known simply as Rolando, has signed for Inter on loan from Porto.
"Since beginning his career at Belenenses, he has acquired a wealth of experience at Porto, Napoli and with Portugal, and will now further strengthen Walter Mazzarri's defensive options.
"The centre-half is due to start training with the Nerazzurri when they return from their US tour."
Rolando has made 110 league appearances for Porto.