Bella Bayliss (née Comerford, born 1 November 1977) is a professional triathlete from the United Kingdom.
She competes in World Triathlon Corporation (WTC) Ironman and Ironman 70.3 triathlons.
An Ironman triathlon consists of a 2.4 mi (3.8 km) swim, 112 mi (180.2 km) bike and a 26.2 mi (42.2 km) run.
An Ironman 70.3 triathlon consists of a 1.2 mi (1.9 km) swim, 56 mi (90.1 km) bike and a 13.1 mi (21.1 km) run.
Bella's time of 8:51:17 at Ironman Austria 2008 was the 2nd fastest women's time in the world in the WTC Ironman 2008 series where 6,223 women finished.