"As you can see now it's official, this is me finally saying after all the rumors... I have officially joined LIV Golf," Rahm told Fox News.
Rahm's announcement ended weeks of speculation that the player who had previously pledged his loyalty to the PGA Tour would sign for the Saudi-backed circuit.
LIV Golf issued a statement saying details for a team captained by Rahm in the coming season, which starts on February 2 at LIV Golf Mayakoba in Mexico, will be released soon.
Big money deal
Two-time major-winner Rahm, whose deal was reportedly worth between $300 million and $600 million, becomes one of the biggest stars to join LIV, the upstart circuit whose emergence has upended the golfing world over the past two years.
His move comes as the PGA Tour and the Saudi backers of LIV Golf attempt to finalise the details of their bombshell merger announced in June.
A deadline of December 31 has been set to agree a framework for the new PGA-LIV joint venture.
The Wall Street Journal speculated Rahm's signing could either be a tactic by LIV's backers to force the PGA Tour to conclude a deal by the agreed deadline, or a move to give fresh impetus to the rival circuit in 2024 if the proposed joint tie-up collapses.
"LIV Golf is here to stay," LIV Golf Chief Operating Officer Lawrence Burian said in a statement. "The addition of Jon reemphasizes that our League is not slowing down. We are continuing to invest and build aggressively for LIV's long-term and exciting future.”
The possibility of Rahm jumping ship to LIV had once seemed unthinkable.
While LIV successfully recruited major winners such as Brooks Koepka, Phil Mickelson, Dustin Johnson, Bryson DeChambeau and Cameron Smith, Rahm had been one of the most staunch PGA loyalists, repeatedly stating that the riches offered by LIV held no appeal when balanced against the tradition of the PGA Tour.
"I laugh when people rumor me with LIV. I've never liked the format," Rahm said earlier this year.
Asked in his Fox interview on Thursday about his past criticism of LIV's 54-hole, shotgun start format he said he'd be discussing it with LIV officials, but had made his peace with it.
'Ambitious, not greedy’
"I know captains have a say and I know they listen to their players, right," Rahm, clad in a LIV Golf jacket for his remote interview, said. "You're part of the organization. So, I'm looking forward to actually having some conversations and giving them my opinion and maybe seeing some changes for the best in the future.
"I'm an ambitious person, but I'm not a greedy one," Rahm said. "I know I can't have everything. So there's some things I'll have to sacrifice and for right now, that seems one that I can live with.”
Last year, Rahm said he had discussed the possibility of a move with his wife Kelley and decided to remain firmly in the PGA Tour camp, saying the huge monetary compensation offered by LIV wasn't enough of an attraction.
In February last year, Rahm had given a categorical assurance he would remain with the PGA Tour, saying he pledged "fealty" to the established circuit.
"They've spent a lot of time in meetings and phone calls and learning about what the future of the game may look like," Rahm said, adding that there "wasn't anything personal" in his decision.
"My goal with this is to grow the game of golf," he said. "To make it better, whatever that may be."