Who Is Rory McIlroy's Caddie? Meet Harry Diamond

The proud owner of five Major championships and closing in on 50 professional victories worldwide, Rory McIlroy has enjoyed a Hall-of-Fame career since turning pro in 2007.

Remarkably, throughout that 20-year timeframe, the Northern Irishman has only worked with two long-term caddies.

The first of which was JP Fitzgerald, who McIlroy brought on board in 2009. During their time together, McIlroy claimed his first four Majors as well as a FedEx Cup and three Race To Dubai titles.

But, following his first winless season since 2008, McIlroy and Fitzgerald parted ways in 2017 and a new bagman arrived on the scene.

It was expected to be a short-term alliance at first, but McIlroy's current caddie, Harry Diamond has largely been with him ever since.

Another of his friends, Niall O'Connor, temporarily carried McIlroy's bag in 2022 - during which time they won the RBC Canadian Open together - but Diamond quickly returned.

O’Connor, a friend who met McIlroy in his late teens, also caddied for the Northern Irishman at the 2019 DP World Championship in Dubai. He played high-level rugby for Ulster and is also a keen golfer. That partnership came about because Diamond was expecting a second child with his wife.

HOW DID MCILROY AND DIAMOND MEET?

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

While McIlroy went on to enjoy a sterling pro career following heady days as an amateur, Diamond was also an outstanding player in his own right, representing Ireland as a youngster.

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

Although it didn't work out for Diamond as a golfer, he stayed in touch with McIlroy and the pair have achieved so many great things on a golf course together.

And given they've known each other for so long, they have a fantastic relationship and understanding on the golf course as well as off it.

Briefly explaining the pair's dynamic, McIlroy once said: "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.”

As well as being on McIlroy's bag, Diamond was also by his side as Best Man when his boss married Erica Stoll in County Meath in 2017. Diamond enjoyed a spell off studying yardage booklets to arrange the stag party in Miami, too.

WHO IS HARRY DIAMOND?

Away from the course, Diamond is fairly private, staying away from social media and saying very little about his work with McIlroy.

He is believed to own a number of his own businesses, including several bars, but has seldom spoken in interviews over the years and prefers to keep the limelight on McIlroy.

IS HARRY DIAMOND A GOOD CADDIE?

Well, McIlroy certainly thinks so. Diamond has come in for spells of criticism during his time working with the former World No.1, unfairly according to McIlroy, and the pro has leapt to his assistant's defence each time.

Before The Masters in 2026, McIlroy said: "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."

Possibly the most high-profile occasion where fans and certain sections of the media were calling for a change on the bag arrived following McIlroy's late collapse at the US Open in 2024.

Some external parties felt that McIlroy may have to move on from Diamond if he wanted to win another Major, with one particular bone of contention being a crucial club choice in the closing holes at Pinehurst No.2 which may have cost the Northern Irish duo dear.

Nevertheless, McIlroy stood firm and fiercely defended his best friend and caddie, calling out a couple of detractors by name. He said: “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 example of the expertise Diamond brings arrived during the closing stages of the 2021 Wells Fargo Championship where the caddie talked McIlroy into taking a penalty drop at the 72nd hole. McIlroy readjusted to find the green and ultimately won the tournament.

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."

Almost certainly the duo's best year to date was 2025. McIlroy bagged his sixth Race To Dubai title later in the year after opening up 2025 with success at the Pebble Beach Pro-Am and The Players Championship.

But it was their triumph at The Masters - the one glaring omission from the pair's partnership - which justified McIlroy's belief in his buddy.

In the aftermath of McIlroy's historic win, he had some warm words 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 12 months later, ahead of The 2026 Masters, McIlroy reiterated how high a regard he holds Diamond in - particularly 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 won 20 professional titles together as well as helping Team Europe to win the Ryder Cup home and away.