The race began at Stormont at 9am with participants beginning their 26.2-mile challenge through the north, south, east and west of the city, with the finish in Ormeau Park.
Thousands more lined the streets to cheer on those taking part and soak up the atmosphere.
It proved to be a great day for athletes across the island of Ireland and beyond, with Tilahun Nigussie winning the marathon in a time of 2:13:37.
Aaron Hanlon of Drogheda and District AC followed in a time of 2:27:06 and in third place was Stephen Connolly of Annadale Striders in a time of 2:29:30.
For the ladies, Millicent Kibet came in first in a time of 2:38:30. In second place, Lalla Aziza Alaoui Selsouli finished in a time of 2:38:51. Gladys Ganiel of North Belfast Harriers was third in a time of 2:45:46.
Congratulations also to Jayne Bleakley who was the first female wheelchair participant to take part in the events history who came in a time of 2:29:28. Karol Doherty won the male wheelchair race.
Check out these colourful images from the big event.
29. Belfast City Marathon
Pacemaker Press 04-06-2025: The 43rd Belfast City Marathon has started with thousands of runners aiming to complete the 26.2-mile course. The race started at Stormont at 9:00 BST and will finish in Ormeau Park. Record numbers have taken part this year - organisers say 6,500 full marathon runners signed up along with 2,750 relay teams (which have between two and five people in them) and 1,200 walkers. Picture By: Arthur Allison /Pacemaker Press. Photo: Arthur Allison / Pacemaker Press
30. Belfast City Marathon
Thousands turned out for the Belfast City Marathon. Photo: Arthur Allison / Pacemaker Press
31. Belfast City Marathon
Thousands of runners set off from Stormont. Photo: Arthur Allison / Pacemaker Press
32. Belfast City Marathon
Seizing the moment at the Belfast City Marathon. Photo: Kelvin Boyes / Press Eye