Alongside four-time major winner McIlroy, who was the 2014 champion at Wentworth, reigning US Open champion Matt Fitzpatrick is confirmed alongside former US Open winner Jon Rahm.
Danny Willett, the 2016 Masters champion, and defending BMW PGA champion Billy Horschel are also scheduled to compete.
“I look forward to competing again at the BMW PGA Championship,” said McIlroy.
“It’s an event I always love playing. The West Course has been good to me in the past, and the fans are incredibly supportive.”
McIlroy’s decision to play in the BMW Championship comes after a wild week, which saw Cameron Smith win the 150th Open in spectacular fashion. But suddenly the headlines turned to whether the Australian was joining Greg Norman’s LIV Golf Series.
While Smith could yet join the tour, Henrik Stenson rocked the golf world by signing up for the LIV Golf Series and was stripped of his Ryder Cup captaincy.
The defection has plunged the Ryder Cup into further chaos, with the historic tournament shaping to be a shadow of its former self.
The event in Italy starting on September 29, 2023, will be billed as Europe’s chance to exact revenge for a humbling defeat last year at Whistling Straits but who will be in the field is anybody’s guess.
Stenson was stripped of his role as Europe’s team captain while fellow European stars Lee Westwood, Ian Poulter, Sergio Garcia and Graeme McDowell all risk being omitted from future Ryder Cups.
As things stand Americans Phil Mickelson, Dustin Johnson, Bryson DeChambeau, Patrick Reed and Brooks Koepka will not be in the frame for selection for the US team at the event at the Marco Simone Golf and Country Club in Rome.
The US PGA Tour swiftly suspended its defectors last month, effectively ruling them out of competing in the biennial team competition because they will not be able to earn the points to qualify.
The DP World Tour, formerly the European Tour, imposed heavy fines on its members who played in the inaugural LIV event in London and banned them from three events.
But the punishments have not stemmed the tide of players signing up to the Saudi-funded LIV series and it is difficult to predict how things will unfold as golf’s civil war deepens.
Wednesday’s announcement that Stenson was jumping ship, and would play in the third event of the LIV series in Bedminster, New Jersey, next week was a bitter blow for golf’s establishment.
The 46-year-old Swede, appointed captain in March, said he accepted the decision even though he disagreed with it.
“I sincerely hope a resolution between the tours and its members can be reached soon and that the Ryder Cup can act as a mechanism for repair amongst various golfing bodies and their members,” he said.
Westwood and Garcia have said they see no reason why competing in LIV tournaments should rule them out of future trans-Atlantic matches and with 14 months to go there is time for a compromise to be reached.
But US Ryder Cup captain Zach Johnson has given a clear steer that players must qualify for the team through the PGA Tour.
– Ryder Cup prestige –
The Ryder Cup is golf’s pre-eminent team event in an overwhelmingly individual sport, bringing together 12-member teams from the United States and Europe every two years for the three-day event.
Colin Montgomerie, speaking before Stenson was stripped of his role, told Sky Sports that being captain of the Ryder Cup team was the “greatest honour that can be bestowed on any European Tour player”.
Padraig Harrington, whom Stenson replaced as skipper, said he wished his former European team-mate had waited until after the 2023 tournament to move to LIV.
Despite his disappointment, Harrington sounded upbeat, telling Sky: “He has given us plenty of time. Fifteen months is loads of time for us to get somebody in place, to get a feel for what they’re doing and it won’t interfere at all.”
But former European captain Tony Jacklin, who twice led the team to victory, has warned that the Ryder Cup could be badly damaged.
“The way things stand right now, next year’s Ryder Cup is just going to be a nonsense,” the two-time major winner wrote in the Telegraph.
“The whole sorry saga is a real mess and the only way it’s going to be settled is through the courts,” he added.
Former world number one Jon Rahm expressed his anger over the situation at last week’s British Open after his fellow Spaniard Garcia confirmed his intentions to quit the DP World Tour, a move that would end his chances of playing in the Ryder Cup.
“The Ryder Cup is the reason why my family and I began to play this sport and the reason why many others play golf,” said Rahm.
“For what is happening to mean that the best player Europe has had (Garcia) can’t play is something I find hard to understand and process.
“The event which gives golf most publicity all over the world is the Ryder Cup and that for this nonsense players like him can’t play it, that angers me even more.”