Barnsley-born Roberts joins from Halifax Town - where he became a real stalwart in the heart of the Shaymen's defence.
After signing his three-year contract, the 24-year-old told Barnsley Player. "I'm happy to get it sorted and I can't wait to get going.
"I've always wanted to sign for my hometown club, and now it's finally here - I can't wait.
"I've got a lot of friends who are Barnsley fans so I've always looked out for their results."
Over the past two seasons, the central-defender has made 93 appearances for Halifax Town, where he attracted interest from Championship Clubs.
"The gaffer here is great and I'm looking forward to working for him," he added. "I had a conversation with him and it tipped it in Barnsley's favour.
"I'm an old-fashioned defender. I'm strong in the air and won't lose many headers. I'm not bad on the floor but I'm looking to improve."
