The 24-year-old left-back made 18 appearances during his single season with the Iron.
"Callum has got a wonderful left foot and he can take set-pieces," Dons boss Neal Ardley told the club website.
"If we can get him moving up the pitch in advance of the wide players then I am sure he will be delivering quality.
"There were not many left-backs out there that fitted our budget and criteria."
- Sports & Recreation
- Neal Ardley