Earlier this year, it was revealed that Tony Mowbray would depart his role on a temporary basis due to medical reasons, his assistant Mark Venus taking over in the short term.
However, with Mowbray opting to focus on his recovery, a decision has been made - which was supported by Mowbray - to bring in Rowett on a deal until the end of the season.
Rowett is no stranger to the West Midlands outfit having been manager between October 2014 and December 2016, recording 42 wins from his 106 matches in charge.
At the time, the former defender was surprisingly removed from his role when Blues were challenging for promotion, the appointment of Gianfranco Zola proving to be a failure.
Nevertheless, Rowett has now taken on the challenge of trying to move Birmingham away from the Championship relegation zone, the club only outside of the bottom three on goal difference.
Co-owner and chairman Tom Wagner told the club's official website: "The Board and Club Leadership fully support Tony's decision to take time to focus on his health and his family. We continue to wish Tony and his family the very best.
"Based on Tony's decision to take some additional time away, we agreed it is in the Club's best interests to appoint Gary Rowett to lead the team forward from the touchline for the final eight games of the season. Gary is an experienced leader and has our full support."
The 50-year-old has been out of a job since October when Millwall made the decision to bring his four-year spell at The Den to an end with the Lions failing to mount a promotion push.
Birmingham are not back in action until March 30 when they make the trip to relegation rivals Queens Park Rangers.