Marrone spent last season at the Neroverdi on a co-ownership agreement but will now return to Juve after the Serie A champions bought the remaining 50 per cent of his transfer rights.
The 24-year-old has signed a five-year deal with the Bianconeri, with Juventus paying Sassuolo €5 million over the course of three years to acquire the midfielder's signature.
Peluso, meanwhile, has agreed a permanent deal to move to the Citta del Tricolore for a total fee of €4.5m.
"Juventus Football Club and U.S. Sassuolo Calcio have today reached an agreement on two transfer deals concerning Luca Marrone and Federico Peluso," a statement on Juve's official website read.
"Marrone, who spent last season on a co-ownership agreement with the Neroverdi, will return to Juventus after the club paid a €5 million fee for the remaining 50 per cent of his transfer rights. He has signed a five-year contract.
"Peluso, meanwhile, will join Sassuolo on a permanent basis after both clubs agreed a €4.5m fee payable over three years for the defender's services."