The former US Open and Masters champion had originally said he was joining the likes of Rory McIlroy, Jon Rahm and Collin Morikawa in sticking with the PGA Tour.
However, in a last-minute change of mind, Johnson has committed to the launch of the Saudi-backed LIV Golf Invitational at Centurion Club near St Albans.
The 37-year-old is one of two world top-20 players set to tee up in the $25 million event, the other being 2010 Open champion Louis Oosthuizen.
The list of major winners also includes Oosthuizen’s compatriot, Charl Schwartzel, as well as European trio Sergio Garcia, Graeme McDowell and Martin Kaymer.
In total, the field is set to include 16 of the world's top 100, with others listed including former world No 1 Lee Westwood, Europe’s Ryder Cup talisman Ian Poulter and Americans Kevin Na and Talor Gooch.
Richard Bland, last year’s British Masters champion, had already indicated that he’d be playing despite having a release request blocked by the DP World Tour.
But some surprise names among the European contingent include 2021 Ryder Cup team member Bernd Wiesberger, recent two-time winner Pablo Larazabal and his fellow Spaniard, Adrian Otaegui.
Six spots in the 48-man field have been left open, meaning there is still a possibility that Phil Mickelson could be added to the field.
“Free agency has finally come to golf,” said Greg Norman, CEO and Commissioner of LIV Golf. “This is an opportunity to start a movement that will change the course of history by bringing new and open competition to the sport we all love.
“The desire shown by the players to participate in LIV Golf demonstrates their emphatic belief in our model and confidence in what we’re building for the future.
“We couldn’t be happier at the diversity of our field, featuring players from around the world, including major champions and those making their debut with us competing in their first professional event.
“We can’t wait to start our journey at Centurion Club with this group of first movers who are committed to growing the game in new and exciting ways.”
It has emerged that the Royal Bank of Canada appears to have severed its links with Johnson, having been one of his main sponsors since 2018.
In a statemet, the company said: “RBC is a proud partner of the PGA Tour. Our partnership is anchored with two world-class golf tournaments – the RBC Heritage and the RBC Canadian Open.
"The PGA Tour has been clear about its intentions in accordance with its tournament regulations should a golfer choose to play in a tournament outside the tour, including the LIV Golf Invitational Series.
“We were recently made aware that Dustin Johnson made the decision to play the LIV Golf Invitational Series opener. DJ has been a valued RBC team member since 2018. While we are extremely disappointed in his decision, we wish him well.”
Westwood and Oosthuizen both lost long-time sponsor UPS after it became known that they were signing for the Saudis.