The 25-year-old centre-back will join the Ibrox club from the start of next season after completing his medical yesterday.
Souttar capped his return from a series of career-threatening injuries by scoring for Scotland on his first international start in over three years against Denmark in a World Cup qualifier at the tail end of last year.
After beginning his career at Dundee United, Souttar moved to Tynecastle in January 2016 and has since made 148 appearances for the Jambos, scoring five goals in the process.
He has been in brilliant form form so far this season and will remain a Hearts player until the end of the campaign.
However, Souttar’s five-year stay in the capital will come to an end this summer as he prepares to link up with Giovanni van Bronckhorst’s side.
Sporting Director, Ross Wilson, commented: “We are really looking forward to John joining Rangers and continuing his development under Gio, our coaching and support staff.
“John is a full Scotland international and has so much potential ahead for the coming years.
“I have really enjoyed getting to know John across all of our conversations so far and I can see how excited he and his family are to be joining Rangers. We are equally excited to welcome John to Ibrox.”
GlasgowWorld previously reported the Light Blues were in pole position to secure Souttar’s signature ahead of interest from several English Championship clubs.
It is believed Souttar held talks with Sheffield United and Blackburn Rovers over a potential move south of the border, but he has opted to remain in Scotland, with Ibrox now confirmed as his next destination.
It appears unlikely that both clubs will agree a deal for Souttar to move to Rangers permanently before the end of the January transfer window.
A statement released by Hearts last night read: “The club reiterates that John is an important member of the firs-team squad and will remain so until the end of the season unless a significant and satisfactory offer is made during the January transfer window.
“No further comment will be made at this time.”
Souttar become Van Bronckhorst’s second January addition, following James Sands’ arrival on loan from New York City.
Souttar’s arrival could spell the departure of fellow centre-half Connor Goldson, who has only six months remaining on his current deal.
The former Brighton man has been a mainstay in the side in recent seasons and played a leading role in the Scottish champions unbeaten domestic campaign last term.
Negotiations over a new contract have seemingly hit a brick wall and it is becoming increasingly likely the Englishman will move on in the summer.