The prop forward, who has signed a two deal with the Region, will join up with the Rodney Parade outfit in the Summer of 2016 during their pre-season preparations.
Hobbs makes his way to the Dragons after making over 100 appearances for Cardiff Blues. He made his debut for the Blues against Edinburgh in 2009. Prior to his time at Cardiff Blues he had an impressive run in the Premiership with Pontypridd.
The Brecon born forward has also represented his country at age grade with international honours from Wales U19s and U20s.
After signing his contract, Hobbs commented: “I am really looking forward to the new challenge ahead at Newport Gwent Dragons. There are good people, good coaches and a strong squad along with some great training facilities and a fantastic support base.
He continued: “I would like to thank everyone at Cardiff Blues for the continued support they have given me throughout the years I have been with the Region.”
Dragons Director of Rugby, Lyn Jones added: “I have always been impressed with Sam as an all round player.
“When we were made aware of his availability, we had no hesitation in making him an offer to stay in Wales, beating off offers from England.
“He will add a great deal of experience and character to a maturing Newport Gwent Dragons squad.”