Caiff y timau troseddau ieuenctid eu grwpio isod yn ôl rhanbarthau’r llywodraeth ar gyfer asiantaethau datblygu rhanbarthol.
- Cymru - Abertawe, Bro Morgannwg, Caerdydd, Caerffili a Blaenau Gwent, Casnewydd, Castell-nedd Port Talbot, Cheredigion, Conwy a Sir Ddinbych, Gwynedd ac Ynys Môn, Merthyr Tudful, Pen-y-bont ar Ogwr, Powys, Sir Benfro, Sir y Fflint, Sir Gaerfyrddin, Rhondda Cynon Taf, Tor-faen a Sir Fynwy, Wrecsam
- Dwyrain Lloegr - Bedfordshire, Cambridgeshire, Essex, Hertfordshire, Luton, Norfolk, Peterborough, Southend, Suffolk, Thurrock
- Dwyrain Canolbarth Lloegr - Derby City, Derbyshire, Leicester City, Leicestershire, Lincolnshire, Northamptonshire, Nottingham City, Nottinghamshire
- Llundain - Barking and Dagenham, Barnet, Bexley, Brent, Bromley, Camden, Croydon, Ealing, Enfield, Greenwich, Hackney, Hammersmith & Fulham, Haringey, Harrow, Havering, Hillingdon, Hounslow, Islington, Kensington & Chelsea, Kingston Upon Thames, Lambeth, Lewisham, Merton, Newham, Redbridge, Richmond-Upon-Thames, Southwark, Sutton, Tower Hamlets & City of London, Waltham Forest, Wandsworth, Westminster
- Gogledd-ddwyrain Lloegr- Darlington, Durham, Gateshead, Hartlepool, Newcastle upon Tyne, North Tyneside, Northumberland, South Tees, South Tyneside, Stockton-on-Tees, Sunderland
- Gogledd-orllewin Lloegr- Blackburn, Blackpool, Bolton, Bury, Cheshire, Cumbria, Halton/Warrington, Knowsley, Lancashire, Liverpool, Manchester, Oldham, Rochdale, Salford, Sefton, St Helens, Stockport, Tameside, Trafford, Wigan, Wirral
- De-ddwyrain Lloegr - Bracknell Forest, Brighton & Hove, Buckinghamshire, East Sussex, Kent, Medway, Milton Keynes, Oxfordshire, Reading, Slough, Surrey, Wessex, West Berkshire, West Sussex, Windsor & Maidenhead, Wokingham
- De-orllewin Lloegr - Bath & NE Somerset, Bournemouth & Poole, Bristol, Cornwall & the Isles of Scilly, Devon, Dorset, Gloucestershire, North Somerset, Plymouth, Somerset, South Gloucestershire, Swindon, Torbay, Wiltshire
- Gorllewin Canolbarth Lloegr - Birmingham, Coventry, Dudley, Sandwell, Shropshire & Telford/Wrekin, Solihull, Staffordshire, Stoke on Trent, Walsall, Warwickshire, Wolverhampton, Worcestershire & Herefordshire
- Swydd Efrog a Humberside - Barnsley, Bradford, Calderdale, Doncaster, E Riding of Yorkshire, Hull, Kirklees, Leeds, North East Lincolnshire, North Lincolnshire, North Yorkshire, Rotherham, Sheffield, Wakefield, York