Rory McIlroy Grand Slam Odds: Why Calendar Slam Is Now A Real Possibility

Rory McIlroy finally joined golf’s most elite club by winning the Masters and completing the career Grand Slam. It was his fifth major title , but remarkably, his first in 11 years since lifting the PGA Championship trophy in 2014.

At that time, McIlroy had just won back-to-back majors and was tipped to dominate the sport for the next decade. But what followed was a rollercoaster of near misses, heartbreaks and inconsistency. That all changed at Augusta in 2025, though not without drama.

McIlroy’s Masters victory was a wild ride. He made four double bogeys , the most ever by a champion, and when he dunked a wedge into the creek on 13 with the tournament at his mercy, it looked like another major meltdown was on the cards. A bogey on 14 followed, and the Grand Slam dream appeared to be slipping away.

But Rory rallied. With some of the greatest iron shots you’ll ever see on the biggest stage of all, he birdied 15 and 17. That left him needing just a par on 18 to win it outright.

Instead, another wayward wedge from 125 yards landed in the bunker, leading to a missed par and a playoff with Justin Rose. That’s when McIlroy finally delivered. He played the 18th hole perfectly in the playoff and rolled in a five-footer to become the first golfer since Tiger Woods to complete the Career Grand Slam.

Now the talk has turned to the unthinkable – could Rory win all four majors in 2025 ?

Rory McIlroy Grand Slam Odds – Can Rors Pull Off Calendar Slam?

Rory McIlroy is 33/1 to win the calendar grand slam in 2025 by winning all four major championships.

It might sound like wishful thinking, but take a look at the upcoming major championship venues and you’ll see why optimism is justified:

• PGA Championship (May 15–18) at Quail Hollow – McIlroy’s favourite hunting ground. He’s won here four times, including his first ever PGA Tour victory in 2010. McIlroy is the 4/1 favourite to win the PGA Championship at Quail Hollow.
• U.S. Open (June 12–15) at Oakmont – a course that demands elite driving. That’s Rory’s biggest strength, and if he's in form, he could separate from the field here. At Oakmont, McIlroy is the joint favourite with Scottie Scheffler at odds of 5/1.
• The Open Championship (July 17–20) at Royal Portrush – McIlroy holds the course record (61) here, set when he was just 16 years old. At the final major of the year, McIlroy is once again favourite, this time at odds of 4/1.

With Augusta conquered and the schedule lining up beautifully, the calendar Grand Slam doesn’t feel out of reach.

Rory McIlroy Major Specials Odds

Despite plenty of optimism from golf fans surrounding what McIlroy could be capable of at the majors this year after his Masters win, there is a dose of reality to be found from the oddsmakers. They suggest that the Holywood native not winning any more majors in 2025 is the most likely outcome with odds of 4/6 on just one more for Rory this year.

McIlroy winning at least one more major is viewed as a very likely chance however with odds of 10/11 on him winning at least one of the remaining three major championships.

If you think he will be a top performer in the big events this year you may well be interested in odds of 11/2 about McIlroy finishing top 5 (including ties) in all 4 majors this year. A 3+ major year is rated as a 15/2 chance.

Grand Slam Odds Watch: Spieth, Mickelson, Rahm & Johnson

McIlroy may have checked the Grand Slam off his list, but several big names are still chasing that elusive accolade.

Jordan Spieth

• Needs: PGA Championship
• Major Wins: Masters (2015), U.S. Open (2015), The Open (2017)
• 2025 PGA Championship Odds: 40/1
• Chances: Still capable, but he has not performed at majors since a T4 finish at the Masters in 2023. He has also failed to crack the top 30 in the PGA Championship since 2019, which suggests the way the tournament is set up is not suiting his game.

Phil Mickelson

• Needs: U.S. Open
• Major Wins: Masters (2004, 2006, 2010), PGA Championship (2005, 2021), The Open (2013)
• 2025 U.S. Open Odds: 250/1
• Chances: He’s finished runner-up six times at the U.S. Open. At 54, history is against him – but never say never with Lefty. He was also 250/1 in 2021 pre-tournament when he won the US PGA Championship for the 2nd time.

Jon Rahm

• Needs: PGA Championship, The Open Championship
• Major Wins: U.S. Open (2021), Masters (2023)
• 2025 Major Odds:
  • PGA: 14/1
  • The Open: 12/1
• Chances: Should be in his prime, but his form has somewhat dipped in recent times. Can’t be discounted, however, and with a T7 and T14 in his last two major starts, he is still putting himself in the mix

Dustin Johnson

• Needs: PGA Championship, The Open Championship
• Major Wins: U.S. Open (2016), Masters (2020)
• 2025 Major Odds:
  • PGA: 66/1
  • The Open: 50/1
• Chances: Still dangerous in the right conditions. If his ball-striking clicks, he’s a threat.

Other Active Players With Multiple Majors

Some stars aren't quite in Grand Slam territory but are worth tracking:

• Brooks Koepka – 5 majors: 3 PGA Championships, 2 U.S. Opens
• Collin Morikawa – 2 majors: PGA (2020), The Open (2021)
• Scottie Scheffler – 2 majors: Masters (2022, 2024)

They’ve already proven they can win on the big stage. A couple more titles and they’ll be in the Grand Slam conversation.

When Was the Last Calendar Grand Slam?

Only Bobby Jones has ever won all four majors in the same year – back in 1930, when the Grand Slam included the U.S. and British Amateur.

In the modern era, Tiger Woods came closest with his 2000–01 "Tiger Slam" when he held all four major titles at once.

Rory’s in rarefied air now. But with three majors left, all at courses he’s thrived on, a genuine shot at the modern calendar Grand Slam is on the table.

Rory McIlroy’s redemption arc reached its climax at Augusta, but the story may not be finished. With Quail Hollow, Oakmont and Royal Portrush next up – all venues that suit his game – the stars may finally be aligning for golf’s most elusive feat.

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