The 28-year-old joined the Championship side last summer.
The 28-year-old joined the Blues on a free transfer at the end of last season, but has now signed a deal that will keep him at St Andrew's until 2018 with an option for a further year, the official website has confirmed.
The news of Maghoma's extended deal will be a big boost for Gary Rowett as he looks to start preparing for next season as the wide-man has been extremely useful this term.
His five goals in the Championship means that only Clayton Donaldson and Jon Toral have scored on more occasions this year. And with the latter returning to Arsenal at the conclusion of his loan spell, the Blues will certainly be looking to keep as many of their goalscorers at the club as possible.
With Birmingham's play-off challenge fading away in the final weeks of the season, Rowett will be looking to the likes of the former Sheffield Wednesday man to maintain a consistent level throughout the next campaign to help the side clear that final hurdle.