The 24-year-old, who was born in Walsall, has signed a "long-term contract extension" with Darrell Clarke's side, but the club has not disclosed the length of the extension.
Roberts progressed through the youth ranks at the Banks's Stadium and has now established himself as a first team regular after his debut at home to Millwall in February 2016.
He's also enjoyed several loan spells, including time at Southport, Gresley and Chester, and is now closing in on 100 Saddlers appearances after achieving his 94th cap against Cambridge on Saturday.
“I’m over the moon to sign the new deal," Roberts said.
“With the start to the season I have had, I’d just like to say a massive thanks to the coaching staff and the gaffer for believing in me and now we can keep pushing on and go on the same journey together.
“I want to keep playing games, I want to keep progressing and I want to keep working hard for this football club.”
Roberts started this season as Clarke's number one, but lost his place in October to on-loan Southampton shot stopper Jack Rose.
He's now regained his spot in the starting XI after solid displays in his last two games.