| Halbro Limited | Construction | 2001 |
| Hall Insulation Ltd | Construction | 2019 |
| Hamlett Construction Limited | Construction | 2021 |
| Hamlett Developments Limited | Real estate | 2024 |
| Hamlett Homes Limited | Real estate | 2025 |
| Happy Days Childcare (Wales) Limited | Health & social care | 2006 |
| Happy Puffin Ltd | Other services | 2021 |
| Harbour Care Services Ltd | Health & social care | 2009 |
| Harbour Lights Management Company (Milford Haven) Limited | Households | 2004 |
| Haven Coast Group Limited | Construction | 2026 |
| Haven Marine Services (Milford Haven) Limited | Manufacturing | 2014 |
| Haven Surveyors Ltd | Professional & scientific | 2021 |
| Havens Head Retail Park Limited | Real estate | 2010 |
| Haverfordwest Auto Centre Ltd | Wholesale & retail | 2025 |
| HE Mechanical Ltd | Administrative & support | 2019 |
| Headzone Limited | Other services | 2014 |
| Heart of Oak (Milford Haven) Limited | Wholesale & retail | 2007 |
| Heavy Pencil Productions Ltd | Information & communication | 2023 |
| Henton Developments Ltd | Real estate | 2024 |
| Herald Online Publishing Limited | Information & communication | 2024 |
| Hicks & Sons Construction Ltd | Construction | 2021 |
| Hiendic Limited | Professional & scientific | 2016 |
| Holiday Homes Pembrokeshire Ltd | Hospitality | 2025 |
| Hollie Jenkins Golf Ltd | Arts & recreation | 2024 |
| Hook Construction (UK) Limited | Construction | 2013 |
| Hope Multiple Sclerosis Therapy Centre | Health & social care | 2008 |
| Houston (UK) Limited | Real estate | 2009 |
| Hubberston and Hakin Hands Together Ltd | Construction | 2022 |
| Hunt Holdings Consultancy Ltd | Professional & scientific | 2023 |
| HV Innovation Group Limited | Professional & scientific | 2023 |
| HW Builders Ltd | Construction | 2026 |
| IAN Kidd Property Limited | Construction | 2014 |
| Ideal Comms Ltd | Financial services | 2018 |
| Ijle Ltd | Wholesale & retail | 2020 |
| Image by Vanessa Limited | Wholesale & retail | 2003 |
| Impasto Pizza Bar Ltd | Hospitality | 2018 |
| Imperial Hall Catering Limited | Hospitality | 2020 |
| Imperial Hall Limited | Real estate | 2018 |
| INJ Limited | Administrative & support | 2019 |
| Inner Tiger Fitness Limited | Arts & recreation | 2024 |
| Investing in Pembrokeshire Society Limited | Arts & recreation | 1998 |
| Iraq Engineering & Construction Limited | Construction | 2003 |
| J & J Construction (Pembs) Ltd | Construction | 2025 |
| J & J Property & Leisure Services Limited | Construction | 2003 |
| J a Properties (Milford) Ltd | Real estate | 2025 |
| J Davies & Co Commercials Ltd | Wholesale & retail | 2023 |
| J G a Dentistry Ltd | Health & social care | 2026 |
| J P Junior Scaffolding Limited | Construction | 2010 |
| J.P. Scaffolding Limited | Construction | 2014 |
| J4 Groundworks Ltd | Construction | 2023 |
| Jackpot Motors Competitions Ltd | Wholesale & retail | 2025 |
| JAM Promotions Limited | Other services | 2013 |
| JAM QW Limited | Other services | 2017 |
| James Bros.,(Milford Haven)Limited | Agriculture & fishing | 1957 |
| Jango's Takeaway Limited | Hospitality | 2025 |
| Jarred Campbell Plumbing and Heating Ltd | Construction | 2023 |
| Jay's Home Support Services Ltd | Public administration | 2024 |
| Jbos Excel Ltd | Administrative & support | 2013 |
| JDM Consultancy Ltd. | Administrative & support | 2021 |
| JE Anthony Ltd | Professional & scientific | 2013 |
| Jess's Horse Haven Community Interest Company | Agriculture & fishing | 2025 |
| Jinked Limited | Other services | 2017 |
| Jmpb Ltd | Professional & scientific | 2020 |
| John Phillips Contractors Limited | Administrative & support | 2012 |
| Johnson’S Off-Road Ltd | Wholesale & retail | 2019 |
| Jolly Sailor (Burton) Limited | Hospitality | 2005 |
| Josa Developments Ltd | Construction | 2019 |
| JP Builders (Pembs) Ltd | Construction | 2026 |
| JP Pilotage Solutions Ltd | Transport & logistics | 2022 |
| JPC Landscapes Ltd | Administrative & support | 2024 |
| K & R Property Management Ltd | Manufacturing | 2014 |
| K and G Motors Ltd | Wholesale & retail | 2026 |
| K. & G. Sutton Contractors Limited | Construction | 1997 |
| KB Events Pembs Ltd | Hospitality | 2023 |
| KD Property Consultant Ltd | Real estate | 2024 |
| Kevcash Limited | Administrative & support | 2022 |
| KGM Welding Limited | Construction | 2020 |
| Kimmeridge Projects Limited | Professional & scientific | 2002 |
| Kirsty Knight Coaching Ltd | Professional & scientific | 2021 |
| Kiru Consultancy Limited | Wholesale & retail | 2023 |
| Kitrick & Co. Limited | Information & communication | 1997 |
| KIZ COM Ltd | Information & communication | 2023 |
| Kona Para Ltd | Hospitality | 2023 |
| Kova Construction Ltd | Construction | 2021 |
| Kt's Bathroom Adaptations Limited | Construction | 2026 |
| Kyanfitt Limited | Arts & recreation | 2024 |
| L a Holmes and Daughters Ltd | Manufacturing | 2022 |
| L.J Home Solutions Limited | Wholesale & retail | 2014 |
| Landskeria Ltd | Construction | 2021 |
| Lansdowne Court (Milford Haven) Management Company Limited | Real estate | 2004 |
| Laserase Carms Ltd | Administrative & support | 2026 |
| LD Properties Pembrokeshire Ltd | Real estate | 2025 |
| LE Saundersfoot Limited | Real estate | 2014 |
| Leah Palmer Hair Ltd | Other services | 2025 |
| Leak in Limited | Construction | 2019 |
| Legal Life Cover Ltd | Financial services | 2019 |
| Legends Tavern Limited | Hospitality | 2023 |
| Letsmove (Pembs) Ltd | Extraterritorial | 2022 |
| Leven Close Management Company Ltd | Real estate | 2016 |
| LGC62 Limited | Professional & scientific | 2007 |