The 48-year-old former RB Leipzig coach will be tasked with avoiding relegation as Leeds sit just two points clear of the red zone.
His arrival, until June 2025, is "awaiting international authorization", specifies the club in a press release.
"I know what a great club Leeds are," Marsch said in a video posted to the club's Twitter account.
"I have ex-players who have played here, I have watched this club from afar for many years and I am truly honored and excited to be here," he added.
"We have a long-term plan and we strongly believe it can take Leeds United to the next level. We can't wait to see what the future holds," said Leeds sporting director Victor Orta.
The club from the north of England, which is in 16th place, is only two steps ahead of the red zone.
Moreover, two of its competitors for maintenance, Everton (17th) and Burnley (18th), have two games late to play.
Five defeats in the last six matches, 60 goals conceded this season: the 4-0 home win against Tottenham on Saturday was the straw that broke the camel's back.
The club chose to separate in the wake of Marcelo Bielsa, the man of the rise in the elite.
Arriving in Leeds in 2018, the Argentinian had failed in the Premier League accession dam in his first season.
In the second, Leeds flew over the Championship (D2), finishing 10 points ahead of their runner-up and returning to the first division 16 years later.
Bielsa's first season in the Premier League saw Leeds finish ninth, with their best points tally at that level since the 2000/2001 season.
But this season, the long injuries including Kalvin Philips, the team's metronome, and Patrick Bamford, his striker, weighed down the "Peacocks".
"Compatible philosophy" with Leeds
Bielsa's successor, Jesse Marsch, was sacked by Leipzig in December after a disappointing five months with the Bundesliga club.
Before being appointed coach at Leipzig, he led Salzburg to the Austrian Cup and League double in 2020 and 2021. With the Austrian club, Marsch was involved in the hatching of Erling Haaland before the Norwegian striker joined Borussia Dortmund in 2019.
"Jesse is someone we identified several years ago during his time at Salzburg and we believe his philosophy and style of football is compatible with the club and will suit the players very well," Orta said.
A former defensive midfielder who has spent his entire career in the United States, Marsch converted to assistant for the American selection in 2010-2011, before serving as head coach, notably at Impact Montreal and the New York Red Bulls.
During a first stint in Leipzig in 2018-2019, he was also assistant to Ralf Rangnick, now Manchester United coach.
© 2022 AFP