The school was formed in 1975 with the merger between Wolaroi Methodist Boys College and the Kinross Presbyterian Ladies' College, Orange (PLC). It is a non-selective school and currently caters for approximately 910 students from the Preparatory school to Year 12, including 280 boarders.
Weymouth House, a small privately owned school for boys, was opened in 1886, on the corner of Byng and Sale Street, Orange. The school was a success, and in 1893 the Wolaroi mansion was purchased, enabling the boys to move to a larger campus. The move led to a change of name for the school, to Wolaroi Grammar School.