The appointment of the 63-year-old German, who was previously head of sports and development for Russian club Lokomotiv Moscow, follows Ole Gunnar Solskjaer’s dismissal earlier this month following a three-year spell as manager in which the club did not win a trophy.
Following his six-month spell in charge, Rangnick will continue in a consultancy role at the club for a further two years.
“I am excited to be joining Manchester United and focused on making this a successful season for the club,” said Rangnick on Monday.
“The squad is full of talent and has a great balance of youth and experience. All my efforts for the next six months will be on helping these players fulfil their potential, both individually and, most importantly, as a team.
“Beyond that I look forward to supporting the club’s longer-term goals on a consultancy basis,” added Rangnick.
Widely considered a pioneer of German football as an early adopter of the “gegenpress” tactical approach, Rangnick has been credited as an influence to Liverpool manager Jurgen Klopp, Chelsea head coach Thomas Tuchel and Bayern Munich boss Julian Nagelsmann among many others.
The German takes over with United currently in eighth place in the league, 12 points behind leaders Chelsea. United and Chelsea shared a 1-1 draw in the Premier League at Stamford Bridge on Sunday.
Rangnick’s arrival has prompted plenty of speculation about Cristiano Ronaldo’s role in the Manchester United team, given the German’s tactical approach.
United’s next game sees them face Arsenal at home in the Premier League on Thursday.
The Manchester club added that Michael Carrick will remain in charge of the first team until Rangnick’s work visa is finalized.