The Serious Crash Unit and WorkSafe have been notified.
St John said it responded with one ambulance, one first-response unit, one rapid-response unit and one clinical support vehicle.
The death has been referred to the Coroner.
There have been at least three other quad bike-related deaths in Hawke’s Bay in recent years including in Wairoa in 2018 and in Central Hawke’s Bay in 2020 and 2021.
Prior to Saturday’s incident, according to WorkSafe, there were seven other quad bike-related deaths around the country during the past 18 months, all on farms.
Crownthorpe is located outside of Hastings and is considered a farming district.