Who Is Rory McIlroy’s Caddie? Meet Harry Diamond

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With five Major championships to his name and nearly 50 professional victories worldwide, Rory McIlroy has undeniably carved out a Hall-of-Fame career since turning professional in 2007.

Remarkably, throughout his impressive two-decade journey, the Northern Irish star has only employed two long-term caddies.

His initial long-term caddie was JP Fitzgerald, whom McIlroy brought on board in 2009. During their partnership, McIlroy secured his first four Major titles, a FedEx Cup, and three Race To Dubai championships.

However, after experiencing his first winless season since 2008, McIlroy and Fitzgerald separated in 2017, leading to a new bagman joining the team.

Though initially intended as a temporary arrangement, McIlroy’s current caddie, Harry Diamond, has largely remained by his side ever since.

In 2022, another of McIlroy’s friends, Niall O’Connor, briefly took over caddying duties, a period during which they notably won the RBC Canadian Open together. However, Diamond quickly resumed his role.

O’Connor, who first met McIlroy in their late teens, also caddied for the Northern Irishman at the 2019 DP World Championship in Dubai. A keen golfer himself, O’Connor previously played high-level rugby for Ulster. This temporary partnership arose because Diamond was expecting his second child with his wife.

HOW DID MCILROY AND DIAMOND MEET?

McIlroy and Diamond are lifelong best friends, having grown up together in Holywood, Northern Ireland, and playing junior golf together at Holywood Golf Club.

While McIlroy progressed from a promising amateur to a celebrated professional, Diamond was also a talented player in his own right, representing Ireland in his youth.

In 2012, Diamond, now a caddie, won the West of Ireland Championship, which earned him a spot in the Irish Open that same year.

Although a professional golfing career didn’t materialize for Diamond, he maintained his close connection with McIlroy, and together they have achieved numerous remarkable successes on the golf course.

Their enduring friendship ensures an exceptional rapport and mutual understanding, both on and off the course.

McIlroy once described their relationship: “I was an only child and Harry was a big brother. We’re very close.

“I love having him on the bag. I’m a different person. And I’m never going to give him sh** even if something goes wrong. It would not be worth it.”

Beyond his duties on McIlroy’s bag, Diamond also served as Best Man when his boss married Erica Stoll in County Meath in 2017. Diamond even took a break from studying yardage booklets to organize the stag party in Miami.

WHO IS HARRY DIAMOND?

Away from the course, Diamond maintains a relatively private life, steering clear of social media and rarely discussing his work with McIlroy.

He is reportedly the owner of several businesses, including bars, but has seldom given interviews over the years, preferring to keep the spotlight firmly on McIlroy.

IS HARRY DIAMOND A GOOD CADDIE?

McIlroy certainly believes so. Despite facing occasional criticism during his tenure with the former World No.1—criticism McIlroy deems unwarranted—the professional golfer has consistently risen to his assistant’s defense.

Prior to The Masters in 2026, McIlroy explained: “I think, as well, because Harry hates the spotlight, hates doing any sort of media, because he’s not as outspoken, people don’t hear from him. So he never has an opportunity to stand up for himself.

“That’s where I step in and I try to be that one that stands up for him because no one knows what he’s doing or thinking or saying because he doesn’t want anyone to know what he is doing or thinking or saying.

“That’s one of the things that I really appreciate about him, as well. He’s obviously a very loyal friend but at the same time he’s doing it solely for the purpose for us to go out there and win Major championships, and big tournaments, and that’s enough for him.”

Perhaps the most high-profile instance of fans and media outlets calling for a change on the bag came after McIlroy’s late collapse at the US Open in 2024.

Some external observers suggested that McIlroy might need to move on from Diamond to secure another Major, with a crucial club choice in the closing holes at Pinehurst No.2 being a particular point of contention that may have cost the Northern Irish duo dearly.

Nevertheless, McIlroy stood firm and fiercely defended his best friend and caddie, even naming a couple of detractors. He stated: “You know, it’s certainly unfair.

“Hank Haney has never been in that position. Smylie has been in that position once. I love Smylie, and he was out there with us on 18, but just because Harry is not as vocal or loud with his words as other caddies, it doesn’t mean that he doesn’t say anything and that he doesn’t do anything.

“I just wish that, you know, these guys that criticize when things don’t go my way, they never say anything good when things do go my way.

“So where were they when I won Dubai earlier year, or Quail Hollow, or the two FedExCups that I’ve won with Harry, or the two Ryder Cups … or whatever? They are never there to say Harry did such a great job when I win, but they are always there to criticize when we don’t win.”

One illustration of Diamond’s valuable input came during the decisive moments of the 2021 Wells Fargo Championship, where he persuaded McIlroy to take a penalty drop on the 72nd hole. McIlroy then recalibrated, found the green, and ultimately clinched the tournament victory.

Reflecting on that moment, McIlroy said: “Harry was awesome out there, especially that decision on the last. I was ready to get in there and try to play that with a lob wedge and he was sort of like, ‘Let’s take a step back, let’s think about this. Where’s the best place you’re hitting your third from?’

“So he sort of calmed me down, slowed me down a little bit and said, ‘pal, let’s just think about this.’ Ultimately we made the right decision.

“It’s Harry and I’s sixth win together and it’s probably been our best one. Bay Hill back in 2018 was great because I hadn’t won in a while, but this is even better just because Harry’s been there every step of the way.”

The duo’s most successful year to date was arguably 2025. McIlroy secured his sixth Race To Dubai title later in the year, having commenced 2025 with triumphs at the Pebble Beach Pro-Am and The Players Championship.

However, it was their triumph at The Masters—the sole glaring omission from their partnership—that truly affirmed McIlroy’s confidence in his close friend.

In the aftermath of McIlroy’s historic win, he offered heartfelt praise for Diamond, saying: “I met him on the putting green at Holywood Golf Club. We’ve had so many good times together. He’s been like a big brother to me the whole way through my life.

“To be able to share this with him after all the close calls that we’ve had, all the crap that he’s had to take from people that don’t know anything about the game, yeah, this one is just as much his as it is mine.

“He’s a massive part of what I do, and I couldn’t think of anyone better to share it with than him.”

Almost a year later, ahead of The 2026 Masters, McIlroy reiterated his immense regard for Diamond, particularly concerning his contributions on the golf course.

McIlroy said: “I think they (the fans and media) don’t understand that he provides a level of comfort on the golf course for me that probably no one else in the world could.

“You know, if I make a mistake, or we make a mistake, I’m much less likely to get angry or get bothered by it because he’s the one on the bag rather than someone else.

“It’s much harder for me to get angry at myself or at him with him next to me than it would be with someone else.”

To date, McIlroy and Diamond have jointly secured 20 professional titles and contributed to Team Europe’s Ryder Cup victories both at home and abroad.