The average age of an olive tree is between 300 and 600 years. However the oldest certified olive tree is more than 2000 years old - Olive tree of Vouves, situated on the island of Crete, Greece. It is probabily the oldest olive tree In the world and still produces olives today.
In New Zealand our oldest olive tree dates back to 1830 when Charles Darwin observed them growing at Waimate North. There are early plantings too in Hokianga, Kerikeri, Snell Beach and Whangarei and the grounds of the Waitangi Treaty House.