McLeish finally ended months of speculation about his future by putting on a new deal which keeps him at St. Andrews until the end of the 2012-2013 campaign.
He guided Blues to promotion from the Championship and then a top 10 finish in the Premier League last season.
Former City player and manager Francis said: "It is great news for Birmingham. It is something supporters have been concerned about for a long time.
"Contractual negotiations seem to get into the open and, once they are in the open, and something is not concluded pretty quickly, it causes concern amongst supporters.
"This has been going on for a long time. I think most Blues supporters expected it to be done during the summer.
"The season has started but I think now it has been concluded, supporters are going to be happy.
"The owners should be very happy and I would think Alex will be quite relieved and relaxed now that it has been finally put to bed."
Francis added: "Alex has been very happy at Birmingham but I think that needs to be recognised by a change in his contract.
"Now Alex can continue his work and the progress he has been making since he came to the club.
"Is it the club's most important signing? Well, I think it is often players that come in from outside who tend to make most headlines.
"But it is often when you re-sign a player, that is as pleasing as when you bring a player in for a manager.
"I think when it comes to a manager signing another contract, it doesn't quite have the same impact as it does with players.
"But I think this is a vitally important deal for Birmingham."