Formerly Chatham House and Clarendon House; the two schools federated in 2009 and the federated school became a new converter Academy from January 2011. A formal proposal to merge was submitted in February 2013 and this was agreed in June 2013. Therefore the schools became one school as of 1st September 2013: Chatham & Clarendon Grammar School.

CCGS is moving from a diamond model to wholly mixed grammar school from September 2025 and is located in central Ramsgate. The school has a reputation for high standards of student behaviour, academic achievement and pastoral care and maintains an enviable programme of extra-curricular provision.