St John Ambulance Cadets is a youth organisation of St John Ambulance founded in England in 1922 for people aged between 10 and 17 to train them in first aid, social actions, wellbeing, communication and other essential skills.

[4] Cadets take part in a variety of activities that consist of providing first aid at community events, learning leadership and training skills.

Cadets can take part in a variety of other activities that are not first aid, and assist adult members of St John Ambulance.

When the new service delivery uniform (SDU) was introduced, the following role bars were available to achieve with training.

The Service Delivery Uniform [commonly abbreviated as SDU] is used for operational activity, it's commonly worn when: The standard issue to Cadets who have not yet completed their Operational First Aider qualification is a branded black polo shirt and a "Cadet" role bar.