The 28-year-old Irishman helped Brentford to the League Two title last year while on a season-long loan from Reading and is confident he can enjoy further success with the Bees after agreeing a two-year deal.
He told the club's official website: "I'm getting towards the peak of my career. I want to push forward and I'm very happy to have a bit of security at a good club.
"I had no doubts I would sign. It probably went on a bit longer than it should have but there was no doubt I would come back.
Bennett has skippered Andy Scott's side during pre-season having also done so towards the end of last term.
He added: "I would say Kevin (O'Connor) is the club captain and I'm happy with that but we have lots of leaders on the pitch. It's a symbol I'm proud to have."