Hatton, a fixture on Europe's last three Ryder Cup teams, is ranked 16th in the world, a six-time champion on Europe's DP World Tour and picked up his maiden PGA Tour title at the 2020 Arnold Palmer Invitational.
He will make his debut on the Legion XIII team this week at LIV Golf's season-opening event at El Camaleon Golf Course in Playa del Carmen, Mexico.
"I'm really excited for this next chapter, to link up with Jon Rahm and Legion XIII, and to get started this week in Mexico," Hatton said in a news release.
Also signing with Rahm's team are American Caleb Surratt, one of the world's leading amateur players, and Zimbabwe's Kieran Vincent, who earned a spot in the league via the inaugural LIV Golf Promotions event last December.
Spaniard Rahm made the jump to LIV Golf from the PGA Tour last December in a big-money move that sent another shockwave through the sport.
"We’ve come a long way in a short period of time and are extremely proud of the team and brand we are building,” said Rahm.
"As we were developing the team’s brand it became clear that I wanted to fight alongside a group of guys who aligned perfectly with what the team stands for.
"Tyrrell is a fierce competitor, proven champion, and of course my Ryder Cup teammate. Caleb is one of the brightest next-gen stars of the game. And Kieran is a steady, talented ball striker who earned his promotion to LIV and is elevating his game every day."
