Places in the amateur races at the Columbia Threadneedle World Triathlon Leeds are almost all sold out after a month of being on general sale.
The Olympic distance race is now full, and just a few spaces remain in the shorter events, which are set for June 11 and 12 next summer.
Nearly 4,000 entries into the amateur races have been sold as Leeds hosting a round of the ITU World Triathlon Series for the first time.
Thousands of spectators are being encouraged to support Britain’s best triathletes as part of their final preparations for the Rio 2016 Olympic Games.
Leeds’ very own Olympic bronze medallist, Jonathan Brownlee, has been involved in designing the course, and is keen to encourage competitors and spectators.
He said: “I want this event to be really special, and the way to achieve that is by lots of people coming out to watch.
“Anyone can enter and do the race on the same course. You will literally be running down the same finishing straight.”
For more details visit leeds.triathlon.org.