Marrone spent last season at Sassuolo on a co-ownership deal, but the 24-year-old will now return to the Juventus Stadium.
The Turin side have paid €5million for full ownership of the midfielder, with Marrone - who has represented Italy at Under-21 level - signing a five-year contract with the Serie A champions.
"Juventus Football Club and Sassuolo have today reached an agreement on two transfer deals concerning Luca Marrone and Federico Peluso," read a statement on Juventus's official website.
"Marrone, who spent last season on a co-ownership agreement with the Neroverdi, will return to Juventus after the club paid a €5million fee for the remaining 50 per cent of his transfer rights. He has signed a five-year contract."
Peluso initially joined Juventus on a six-month loan deal from Atalanta in January 2013, before making the full switch in June of the same year.
However, the left-back has failed to become a regular in Antonio Conte's starting XI, and moves to Sassuolo for a fee of €4.5million, to be paid over three years.