Pierre LeBrun of TSN reported Gallant will receive a four-year deal.
Gallant replaces David Quinn, who compiled a 96-87-25 record from 2018-2021 while helping guide the team's rebuild.
It was an unprecedented end to the season in New York off the ice as the Rangers called on the NHL to relieve George Parros of his duties as the head of the league's Department of Player Safety following an injury to winger Artemi Panarin by Washington Capitals repeat offender Tom Wilson.
New York went so far as to release a statement condemning both the league and Parros for failing to protect players. The NHL responded by fining the club $250,000. Two days later, on May 5, general manager Jeff Gorton and team president John Davidson were fired and replaced by former Rangers star Chis Drury.
A week later, Quinn was fired as head coach along with his three assistants.
Gallant won't find himself in need of a drastic roster overhaul in New York, though. Between perennial Hart Trophy candidate Panarin, natural goal-scorer Mika Zibanejad and 2020 No. 1 overall pick Alexis Lafreniere, the Rangers have plenty of pieces to start contending again in the near future.
That was all because of the work of Gorton and Davidson, and now it's on Gallant and Drury to help finish the job.
Gallant was one of the first coaches to interview for the job in mid-May before taking off to coach Team Canada at the World Championships.
Over nine years as a head coach, Gallant has compiled a 118-75-20 record but has never made it through three seasons with any team.
He was replaced in Vegas after a midseason firing despite leading the team to the Stanley Cup Final during its inaugural campaign in 2018.
Now he gets a chance to build again in New York.