The St. John Ambulance Brigade is a voluntary organisation, non-sectarian and non-political, existing for the purpose of training members of the general public to give First Aid assistance to the sick and injured on public occasions. It is a permanent organisation in time of Peace, ready and available in time of Emergency.

The St. John Ambulance Brigade offers a variety of services from First Aid cover at public events to Training members of the general public in First Aid and many other life saving techniques.

In a suburb located west of Dublin city, a group of like minded adults established Castleknock Combined Division in 1988, with the objective of providing a First Aid voluntary service to the community. A strong family focus rapidly developed, hence the establishment of a vibrant Ambulance and Nursing Cadet (youth) section of the Division.

It was not long before competition fever arrived at the doorstep of the Division. Castleknock has achieved some of the most prestigious competition trophies in First Aid and Caring for the Sick available.