The 25-year-old is a veteran of 85 NRL games, all of which came after he joined the Canberra Raiders in 2013.
The former Italy international hopes he can earn his spot in the forward pack at the Dragons.
“I’m very happy to be joining the Dragons who have such a rich history and looking forward to starting the pre-season alongside my new team-mates,” Vaughan said.
“The focus now is training hard over the coming months to establish myself within a very strong forward pack and playing my role within the squad.”
The Dragons are looking to rebound after missing the top eight this year, while the Raiders were eliminated in the preliminary finals.