This article is about the school in New South Wales, Australia. See also Avondale School (Wiltshire) and Avondale High School (disambiguation) Avondale School is a K-12 co-educational Christian day school in Cooranbong, New South Wales, Australia. It features an Early Learning Centre (preschool) and educates over 950 students each year. It is the oldest continuously operating Adventist school in Australia. It is a part of the Seventh-day Adventist education system, the world's second largest Christian school system.