The 27-year-old has played 81 games in eight seasons with the club he grew up supporting.
“It was definitely one of the easiest decisions I’ve made in my time,” Paul Stewart said.
“It’s great to be basically a one-club player and the chance to stay here with family and friends made it a pretty straightforward call.”
Stewart has played eight games for the Magpies this year and four for the Power.
“My year has been a bit up and down with injury but I’ve really enjoyed the chance to play at AFL level when I’ve been called up.
“I’ve got real trust in Ken Hinkley, Garry Hocking running the SANFL side and the direction the club is going with our footy structure.
“It’s been a great system for us as players to play to the same game plan in the SANFL and the AFL, and it’s good for our supporters who can see the Power play one day and then the Maggies the next.”
Senior coach Ken Hinkley praised Stewart’s versatility and willingness to play whatever role is required.
“Stewie is a well-rounded team player, he offers us a lot in terms of his ability to play many roles,” Hinkley said.
“He’s great for the culture of the group and he works relentlessly at improving his game.”
“Stewie has played good footy in the Magpies and has been unlucky with injuries this year.
“But what we have seen is when he has come in, he’s stepped straight up to the level.”