In 2005, the Principal Mrs Mary Koh together with a selected pool of experienced HODs and Teachers, set about to prepare for the establishment of a new secondary school in Punggol.

In 2006, Greendale Secondary School took in the first batch of Secondary One students.

In December 2008, Mr Mark Gerard Minjoot took over as Principal of Greendale Secondary School, as Mrs Mary Koh was posted to MOE HQ as Cluster Superintendent/Schools Division