McCombe, 27, has signed a three-year contract with the Terriers after the Yorkshire side agreed to pay an undisclosed fee to Bristol City.
"I wouldn't be coming to Huddersfield if I didn't think they would make it to the Championship soon - it's not a quick move nearer to home for me," he told Huddersfield's official website.
"I've moved to a club with the potential to get back to where I want to be. I'm originally from up here and I know all about Huddersfield - it's a great club with big potential and aspirations. I think this club will go onto bigger and better things."
McCombe began his career at the Iron and emerged as one of the club's most exciting prospects under youth coach Paul Wilson, he even had a trial with the Premier League side Aston Villa.
But he fell out of favour after a disagreement with then manager Brian Laws and joined Lincoln City on a free transfer in March 2004. He made a total of 75 appearances for the Iron, scoring five goals
He joined Bristol City two years later, helping them win promotion to the Championship.
McCombe moves to the Galpharm Stadium just after one other former Scunthorpe defender left the club.
Andy Butler formally left the Terriers this week after coming to an agreement to cancel his contract. He has said he would like to move back to Glanford Park, but has been linked with Rochdale.
Jim Goodwin, the former Scunthorpe midfielder, also looks set to leave Huddersfield as he is on the transfer list.