The 21-year-old has penned a three-year deal with Maritzburg and his arrival will help offset the departure of influential centre-back Bevan Fransman.
Fransman's contract with the club expires at the end of June, with SuperSport and Cape Town City rumoured to be after the former Kaizer Chiefs man.
Team of Choice official Quintin Jettoo told KickOff.com: "Denwin has signed a three-year deal plus a one-year option.
"He is a young, talented player. He can play left-back or centre-back."
On Tuesday it was announced that SuperSport had signed Amajita defender Luke Fleurs from National First Division club Ubuntu Cape Town.