Former Manchester United player Ole Gunnar Solskjaer has been confirmed as the club's caretaker manager until the end of the season.
The Norwegian replaces Jose Mourinho who was sacked by United on Tuesday.
Solskjaer, who had been in his second spell managing Norwegian side Molde, made 366 appearances for United between 1996 and 2007.
The 45-year-old will be joined by ex-United assistant Mike Phelan, the club announced on Wednesday.
Ed Woodward, Executive Vice Chairman, described Solskjaer as a "club legend".
"His history at Manchester United means he lives and breathes the culture here and everyone at the club is delighted to have him and Mike Phelan back," Woodward said.
"We are confident they will unite the players and the fans as we head into the second half of the season."
Solskjaer takes the reigns with Manchester United languishing sixth in the Premier League and 19 points adrift of leaders Liverpool.
His first match will be on Saturday away to Cardiff City - a club Solskjaer managed for just nine months in 2014.
Responding to his appointment, Solskjaer said: "Manchester United is in my heart and it's brilliant to be coming back in this role.
"I'm really looking forward to working with the very talented squad we have, the staff and everyone at the club."
On sacking Mourinho, the club said it had intended to recruit an interim manager before making a permanent appointment at the end of the season.
Solskjaer's appointment means he becomes the fourth manager to take charge at Old Trafford since Sir Alex Ferguson retired in 2013.
The Norwegian will be expected to get the best out of a squad of players widely perceived to have been under-performing this season.
He will also be faced with deciding whether to bring back £89.3 million signing Paul Pogba back into the fold following his falling out with Mourinho.
During his time in charge of Cardiff, Solskjaer failed to keep the Bluebirds in the Premier League.
Following Cardiff's poor start in the Championship he was sacked.