Cardiff Half Marathon, live.

Over the barrage, round the lake, home to the castle

A city half that leaves Cardiff Castle, walks across the water to Penarth and comes back through the Bay before one lap of a park lake.

The 23rd Cardiff Half Marathon was run on Sunday 4 October 2026. It starts on Castle Street, outside Cardiff Castle, at 10:00 for the elite, white, green and red pens, with the blue, purple and yellow pens following at 10:10. Pacers carrying sail flags run in every pen, with targets from 1:30 to 3:00. The finish is a grandstand finish in the civic centre, on King Edward VII Avenue. The organiser’s next date on its own site is 3 October 2027.

The route reads like a tour of the city’s waterfront. From the castle it passes the Principality Stadium and Cardiff City Stadium, heads out to Penarth Marina, crosses the barrage and runs into Cardiff Bay past the Norwegian Church, the Senedd and the Wales Millennium Centre. Then it turns north for a full loop of Roath Park Lake before the run back to the civic centre. The organiser calls the course predominantly flat and fast; Powerade is handed out at mile 9, and the half sold out for the ninth time before going to ballot for 2026.

For anyone waiting, the organiser’s own spectator spots are Castle Street near the start, Corbett Road in the closing stages and the tiered terraces on King Edward VII Avenue above the finish. The hard part is knowing when to be where, with two start times and pens stretching across the field. The runner can share a link to their own Livebib broadcast; family and friends open it in a browser, no account and no app, and see the position on the course line, distance covered and a finish estimate that updates as the race goes. Anything estimated is marked as estimated, and the runner decides who gets the link.