Organisers say triathletes from across New Zealand and around the world have registered to take part in the half Ironman.
Entries are still open for the full Ironman New Zealand.
Ironman New Zealand and Ironman 70.3 New Zealand race director Wayne Reardon says he anticipates the remaining entries for the full distance Ironman will be filled quickly following the Ironman 70.3 distance selling out, and last week's announcement of "Voice of Ironman" Mike Reilly's retirement.
"We've been blown away by the demand athletes have shown for December's Ironman 70.3 New Zealand. Taupō has always been a bucket-list place for athletes to race, renowned for its stunning scenery and amazing atmosphere, and this sell-out proves its enduring popularity," Wayne says.
"We encourage athletes to secure their spot quickly as triathletes from around the world have been snapping up entries off the back of the news that Ironman New Zealand will be the last race Mike Reilly will call after 33 years of announcing Ironman events, an occasion many people are desperate to be part of."
The 2022 event will also feature a Kids Fun Run on Friday 9 December. Children aged 5-13 years can run 750m, 1,400m or 2,000m at Tongariro North Domain, Taupō and finish down the iconic Ironman finish chute.