Triathlon
7 of the best triathlons in Ireland in 2025
Keen to put your training to the test? Then have a crack at one of these awesome triathlons.
Listen, you don't need to be Kristian Blummenfelt - AKA the first triathlete to hold both the Olympic and IRONMAN world titles at the same time - to reap the benefits of a swim/cycle/run in that order.
And if you are looking to dip your toe into the waters, Ireland is blessed with an abundance of awesome races taking place up and down the country - almost every weekend during the summer. And it’s not too late to sign up.
To put you in the right direction, we have found some of the very best triathlons for this year. Whether you’re looking for beautiful scenery, a generous distance or in fact a course that will really put you to the test, there is something for everyone.
Heads up: some of these events may be later in the year, but they are still selling out fast, so don't leave it too late and book places well ahead of time.
01
Base2Race Harbourman - 6 July, 2025
Base2Race Harbourman
© Base2Race Harbourman
A great choice for Dublin-based folks, this Olympic-distance race takes place in Wicklow Town. It kicks off from the town centre, with the sprint and with a 1,500m open-sea swim in the harbour. There’s then an out and back 40km cycle and a 10km run route that starts and ends in the town centre.
The event has traditionally been hosted by the good people at Wicklow Triathlon Club, who are always on the hunt for new members. It doesn't matter if you've designs on training for your first tri or making the podium for your tenth, they offer sessions for all ages and abilities. If you live in the area it's a no-brainer.
02
Celtic Warrior Triathlon - 2-3 August, 2025
Olympic? Sprint? Half Iron? However you take your triathlons served, get one fresh and hot when Celtic Warrior comes back to Mullingar, Co. Westmeath at the end of July. There's plenty to choose with triathlon and similar events for all levels.
Billed as Ireland's biggest weekend of long-distance running, cycling and swimming (you can even warm up with a 10k if you fancy it) but the triathlons promise to last long in the memory. Don't go too crazy though. Set around the spectacular Lough Ennell, nobody would blame you for making the most of the scenery.
03
Tri the Hook - 16 August, 2025
Competitors tackle the tide at Tri the Hook
© Tri The Hook Triathlon/Hook Tourism
This is by no means Ireland’s easiest sprint distance course but the scenery is more than dramatic, which is enough to take your mind off the task at hand. The 750m swim takes place in the historic Baginbun Bay and is followed by a tough 20km cycle route that takes in plenty of sharp bends, steep inclines and dips.
The cherry on top of the cake comes in the form of a 5km clifftop run with a number of lung-busting ascents. Now in its 12th year, you won't want to miss it. Scenic? Sweaty? Something to train for? Get it in the diary.
04
The Goat - 23 August, 2025
Test yourself in surroundings like these at the GOAT Triathlon
© GOAT Triathlon
This sprint distance triathlon takes place around Cushendall in the Glens of Antrim, and is ideal for all comers. The swim starts from the Waterford slipway and is patrolled by the RNLI. Competitors then race to their bikes for the 22km ride along the historic coast road and up hilly Glen Ballyeamon, with switchbacks and spectacular views. The race is topped off with a 5km run along the cliff path and back to the beach.
To top if off, entrants will be treated to a free BBQ post-race and there is always a great camaraderie between the competitors.
05
Dublin City Triathlon – 23 August, 2025
The swim at Dublin City Triathlon takes place in the Upper River Liffey
© LE Action Shot
Another triathlon slated to take place on Saturday 23 August is the Dublin City Triathlon. Located inside Phoenix Park, it’s a race that has evolved from a few hardy competitors swimming in South Wall three decades ago to being part of 2025's Triathlon Ireland National Series. As one of the most inclusive events around, it's the ideal triathlon to either bring some friends along or else make some new ones on the day.
Last time out, there were over 1000 entrants and it sold out fast. Tickets are now available so be fast.
06
The Lost Sheep - 30 August, 2025
The Lost Sheep triathlon is as limb-sapping as it is lung-busting
© John O'Shaughnessy.
Few triathlons in the world can match The Lost Sheep for rugged beauty. Known as one of the toughest half iron distance races in the country, competitors kick off with a 1900m swim in Kenmare Bay, before an 83km bike ride along Wild Atlantic Way and up two 'category one' climbs which include the infamous Healy Pass.
Be sure to save some energy though: the 21km run course, which was remapped in 2023, is almost as gruelling as the cycle by all accounts. Expect to be treated to spectacular views as you negotiate the Caha mountains and beyond. It's always a great option if you’re looking to up the ante.
07
Jailbreak Triathlon - 31 August, 2025
Cobh's Jailbreak Triathlon takes no prisoners
© Michael Buckley/Cobh Tri
Don't expect any prisoners to be taken at this novel Triathlon Ireland National Series Race inspired by the iconic Escape from Alcatraz Triathlon over in the US. Open to both teams and individuals, the 'jailbreak' aspect of this triathlon consists of a swim from a former prison island across the world’s second largest harbour.
The event takes place in the historic town of Cobh, in Cork, consisting of a 1500m swim, 40km single loop bike leg and lastly a 10km run along the beautiful waterfront. The race starts and ends in the centre of the town, so expect cheering crowds to help carry you across the finish line.
So, you've chosen a triathlon. What now?
If you want to get fit for purpose and nail any looming triathlon, take note of these handy training guides below.