The Mount Run has distances for runners of all abilities with 5km, 10km and half marathon (21.1km) options.
Mount Festival general manager Lauren Watson said the response to next year's event was "incredible".
"We have the highest entries ever at this time of the year and the online banter for the event is phenomenal. Everyone is so excited to race."
When asked what has led to the response, Watson said: "We started our athlete communications several months earlier than normal, and ran some virtual events during the first lockdown.
"This helped build interest and a strong culture around our event. There is also the fact that people can't travel overseas to race at the moment, so are looking to well established New Zealand events such as the Mount Festival.
"As the country's long-running triathlon, we have become the go-to event for triathletes this summer."
The 2021 Tauranga Half field is the strongest in over a decade with several former champions set to be on the start line at Pilot Bay.
Defending champion and race record holder Kyle Smith is back and faces incredible competition from the likes of 2019 winner Mike Phillips, former race record holder Braden Currie, 10-time champion Cameron Brown and former world champion Terenzo Bozzone.
In the women's field for the Tauranga Half, defending champion Hannah Wells is seeking a three-peat of wins on her home course. Other elite female athletes already confirmed are 2020 runner-up Rebecca Clark and the strong performing Melanie Burke and Emily McNaughton.
The start-line for all Mount Festival events is Mount Maunganui's picturesque Pilot Bay. More than 1500 athletes are expected in Pilot Bay for the various events.
To enter go to: www.mountfestival.kiwi
Mount Festival of Multisport Events
Tauranga Half: 2km Swim, 90km Bike, 21km Run.
Enduro: 3km Swim, 120km Bike, 25km Run.
Aqua Bike: 3km Swim, 120km Bike.
Mount Run: 5km, 10km or 21km.
