All Industry companies in Treharris
- 7 Day Tools - Treharris
- Acorn Travel South Wales Ltd - Treharris
- Astra Plant Ltd. - Treharris
- Astra Plant Wales - Treharris
- Bowen (Contracting) Ltd - Treharris
- Bowen Partners - Treharris
- Brian Thomas Transport Ltd - Treharris
- Calder Building Services - Treharris
- D W R Cymru (Financing) Ltd - Treharris
- Davies Bakery Ltd - Treharris
- Davies's Bakery - Treharris
- Dragonwear - Treharris
- Dwr Cymru Cyfyngedig - Treharris
- Electrech Ltd - Treharris
- Flicks - Treharris
- Gerald Murphy & Son Ltd - Treharris
- Gibbons Coache Holidays - Treharris
- Graham Bridges Welding & Plating - Treharris
- Greens Skip & Fill Services - Treharris
- Greens Skip and Fill Service - Treharris
- Heath Marketing Ltd - Treharris
- Howard Miles Plant Hire - Treharris
- Insight Intelligence Ltd - Treharris
- J T Miles & Sons - Treharris
- Jj Comms - Treharris
- Kits N Bits - Treharris
- Masterfoil Ltd. - Treharris
- Morgan Sindall - Treharris
- Nelson Construction Co. Ltd. - Treharris
- Ryan Stockdale Consulting Ltd - Treharris
- Ryans Carpentry Services - Treharris
- Southern Trimmers - Treharris
- Step-Up - Treharris
- Taff Container Services - Treharris
- Taylors Solid Fuels - Treharris
- Wellington Stores Ltd - Treharris
- West View Stores - Treharris