Gabigol, the 19-year-old Santos forward, landed in the fashion capital earlier in the day to complete his move. Portuguese winger Joao Mario arrived shortly after.
Sky Sport Italia understands Inter will pay a €25-million fee for Gabigol, divided between Santos and the player's family. His father, Valdemir, and agent, Wagner Ribeiro, were also present as fans mobbed the Olympic star at Malpensa airport.
Gabigol is expected to sign a five-year contract with the Italian giant, although he could yet return to Santos on loan until December. Manchester City set up a similar agreement with Palmeiras to acquire fellow gold medalist Gabriel Jesus.
Joao Mario's deal is worth up to €45 million, according to La Gazzetta dello Sport. It marks the end of a complex and long negotiation process which started more than a month ago, with Inter's new Chinese investors pushing for the transfer.
Gabigol and Joao Mario will become the first two signings of the Frank de Boer era, after the Dutchman replaced Roberto Mancini on the bench. The new regime began with an embarrassing loss to Chievo last weekend.