Counties 3 Kent (formerly Kent 1 known as Shepherd Neame Kent 1 for sponsorship reasons) is an English level 9 Rugby Union League and is made up of teams predominantly from south-east London and Kent. The teams play home and away matches from September through to April. The league champions move up to Counties 2 Kent. Relegated teams drop down to Counties 4 Kent. Following the RFU's Adult Competition Review, from season 2022-23 it adopted its current name Counties 3 Kent.

Each year some of the clubs in this division also take part in the RFU Junior Vase - a level 9-12 national competition.

Departing were Tonbridge Juddians II and Beckenham II, both promoted to Counties 2 Kent.

Old Dunstonians (9th in 2024-25) withdrew before the season started.

Departing were Old Elthamians and Old Alleynians II, both promoted to Counties 2 Kent. Faversham (10th) were relegated to Counties 4 Kent.

Joining were Old Dunstonians relegated from Counties 2 Kent together with Beckenham II, Brockleians and Old Gravesendians, all promoted from Counties 4 Kent

Departing were Dartford Valley and Medway II, both promoted to Counties 2 Kent. King's College Hospital (9th) and Footscray (10th) were relegated to Counties 4 Kent.

Joining were Hastings & Bexhill relegated from Counties 2 Kent together with Sittingbourne promoted from Counties 4 Kent and Tonbridge Juddians III who upon joining this league were rebranded as Tonbridge Juddians II.