HMS Cattistock is proud to be affiliated with the following organisations:
- Cattistock Village is located near Dorchester in Dorset in the heart of Thomas Hardy country.
- The Cattistock Hunt owes its origins to Mr JJ Farquharson, who in 1806 undertook Cattistock Country together with the rest of Dorset and began the first pack of hounds. He retired in 1858 and in 1869 Cattistock formed its own separate Hunt. Today, the Cattistock hounds hunt five days a fortnight.
- Trinity School CCF caters for the sixth formers at Trinity school providing extracurricular activities such as climbing, parachuting, infantry courses, solo gliding or flying, sub-aqua courses and challenging leadership courses. The cadets also have the opportunity to gain qualifications in areas like first aid.
- TS Comus - Wallsend Sea Cadets is one of the Ship's two affiliated Sea Cadet units. Providing activities for 10 -18 year olds and the opportunity to gain qualifications in maritime activities such as sailing, powerboating, communications, canoeing, first aid etc
- TS Onslow - Oldham Sea Cadets is the Ship's second Sea Cadet affiliation.
- Lilliput Sea Scouts in Poole is the Ship's newest affiliation having been adopted in August 2005. They cater for Junior Beavers and intermediate Cubs as well as the older Scouts