The 28-year-old is currently on loan at the Premiership returnees from SuperSport United until the end of the season.
“We have come to an agreement with Michael Morton to extend his stay with us for another two years,” Usuthu general manager Lunga Sokhela told the club's website.
“Morton is a player who has shown great commitment to our cause, and we are only happy to keep him.”
Morton, who has scored once in 16 league outings this campaign, is relieved to have sorted out his future.
“I’m just happy to have settled things, I know where my future lies. It’s a nice relief,” said the former Orlando Pirates and Maritzburg United man.
“I didn’t sign for a team that I don’t think is not going to be in the PSL next season. We have to make sure we keep the status by obviously working hard.
“There’s nine games left and we’re not too far now. Everyone’s put-in is going to be important and I just want to play a part in that.”
Cavin Johnson's side are ninth on the Absa Premiership table with 26 points from 21 games, and will look to respond from a 2-0 derby loss to Maritzburg when they visit high-flying Free State Stars at Goble Park on Saturday night.