Bosc, 33, has been with the Dragons his entire career, joining the UTC club pre-Super League era.
He has scored 1169 points in 210 Super League games, and is contracted to the club until the end of 2017.
"I've taken my time before taking a decision but I feel good and I'm ready to start a new season," Bosc said.
"I love this sport, I love this club but I would make sure that my body allowed me to keep playing at this level. I'm sure of my choice now and I'm delighted to stay another season."
Dragons head coach Laurent Frayssinous added: "I'm really happy to keep Thomas at the club next season. He is an important player in our squad, for his versatility at the key positions in the halves, as a hooker or a fullback but also for his qualities and his values."
Half-back Thomas Bosc has signed a one-year contract with Catalans Dragons, and joined the reserve side coaching team as Jerome Guisset's assistant.