The appointment of Langer comes just a month after compatriot Trevor Bayliss, once in charge of the England men's national side, left his role as Spirit boss after overseeing just three wins in the past two seasons of the Hundred.
Opening batsman Langer, 54, played more than a 100 Tests for Australia and also coached his home country from 2018-22, winning two Ashes series and also lifting the 2021 T20 World Cup.
He has previously coached Perth Scorchers in the Big Bash and is head coach of Lucknow Super Giants in the Indian Premier League.
"I'm thrilled to be appointed to this role with London Spirit, and I'm excited to experience The Hundred," Langer said.
"I'm looking forward to being a part of the tournament later this year, and working with such a talented group of players and coaches."
The Hundred, where each team plays 100 ball per innings comprises eight specially created clubs, each featuring a men's and women's teams.
This has proved controversial and a source of frustration to many longstanding English cricket fans as it makes it the only senior domestic men's competition not involving all the traditional 18 first-class counties.
