| Feel Good Magazine Limited | Information & communication | 2019 |
| Feelfree Employment Group Limited | Administrative & support | 2023 |
| Feelfree Storage & Building Ltd | Real estate | 2025 |
| Fehn Ltd | Wholesale & retail | 2015 |
| FEI Foods Limited | Manufacturing | 2010 |
| Felindre Innovations Repairs Servicing & Tackle Ltd | Manufacturing | 2016 |
| Femf Limited | Professional & scientific | 2022 |
| Femhaus Ltd | Other services | 2023 |
| Feminity CIC | Education | 2025 |
| Femmely Ltd | Administrative & support | 2024 |
| Feng Yuan Food Ltd | Hospitality | 2021 |
| Fenny Garage Limited | Wholesale & retail | 2007 |
| Fenris Electrical Limited | Construction | 2024 |
| Fernlee Estates Limited | Construction | 1982 |
| Ferns Aesthetics Ltd | Health & social care | 2020 |
| Ferox Enterprises Limited | Administrative & support | 2011 |
| Ferrara Square Management Company Ltd | Real estate | 2020 |
| Fezza Limited | Wholesale & retail | 2022 |
| FFA Coffi I Bawb CYF | Hospitality | 2015 |
| Ffin Consultancy Limited | Professional & scientific | 2023 |
| Ffin Eyewear Ltd | Wholesale & retail | 2022 |
| Fflwr Botanicals Limited | Arts & recreation | 2019 |
| Fforchdwm Limited | Energy | 2017 |
| Ffordd Y Coed CIC | Other services | 2026 |
| Fforest Auto Swansea Ltd. | Wholesale & retail | 2017 |
| Fforest Construction Group Ltd | Construction | 2023 |
| Fforest Construction Ltd | Construction | 2014 |
| Fforest MOT Centre Limited | Professional & scientific | 2000 |
| Fforest Parc Bakery Limited | Manufacturing | 1990 |
| Ffyniant Group Ltd | Construction | 2025 |
| Ffyniant Logistics Limited | Transport & logistics | 2025 |
| Ffynone Management Limited | Households | 1984 |
| FG Sportswear Ltd | Manufacturing | 2025 |
| FGP Ciuba Ltd | Real estate | 2025 |
| FH Place Limited | Real estate | 2024 |
| Fhortho Limited | Health & social care | 2015 |
| FHS Trust Limited | Education | 1972 |
| Fibreglass Leisure Ltd | Wholesale & retail | 2016 |
| Fidelta Limited | Administrative & support | 2020 |
| Fife Consultancy Limited | Information & communication | 2000 |
| Fight Gear Limited | Extraterritorial | 2014 |
| Fighting Gear Limited | Extraterritorial | 2023 |
| Fighting MAN Films Ltd | Information & communication | 2025 |
| Fighting UN Limited | Extraterritorial | 2014 |
| Fika Health & Wellbeing Limited | Wholesale & retail | 2024 |
| FIL FIL 2019 Ltd | Hospitality | 2019 |
| Film Rigging Action Ltd | Construction | 2021 |
| Filmfinders Media Ltd | Wholesale & retail | 2022 |
| Finalfoods Limited | Manufacturing | 2005 |
| Finalfoods Retail Limited | Real estate | 2025 |
| Finalfoods Wholesale Limited | Manufacturing | 2007 |
| Finance UN Limited | Extraterritorial | 2013 |
| Financial Solutions Wales Limited | Financial services | 2005 |
| Finchlake Property Management Limited | Real estate | 1983 |
| Find Your Balance Limited | Other services | 2021 |
| Fine Dine Ltd | Hospitality | 2010 |
| Finedinestays Limited | Hospitality | 2018 |
| Fineline Technical Management Limited | Professional & scientific | 1989 |
| Finsbury Accommodation Limited | Real estate | 2020 |
| Fiona Mason Consultancy Limited | Professional & scientific | 2020 |
| Fire Investigation Risk Evaluation Consultancy Limited | Professional & scientific | 2014 |
| Fire Protection Services Limited | Professional & scientific | 2006 |
| Fire Safety Direct Limited | Construction | 2003 |
| Firefed Ltd | Hospitality | 2025 |
| Firel Ltd | Manufacturing | 2023 |
| Fireweb Consulting Ltd | Professional & scientific | 2026 |
| Firmlevel Management Company Limited | Real estate | 2003 |
| First 4 Enterprise Limited | Professional & scientific | 2003 |
| First Air Limited | Transport & logistics | 2002 |
| First Camion CYF | Transport & logistics | 2015 |
| First Celtic Properties Ltd | Real estate | 2018 |
| First Choice Body Shop Limited | Wholesale & retail | 2015 |
| First Choice Interiors (Swansea) Ltd | Construction | 2015 |
| First Class Contractors Ltd | Construction | 2021 |
| First Corporate Production Ltd | Manufacturing | 2020 |
| First Cymru Buses Limited | Transport & logistics | 1914 |
| First FIX Interiors Ltd | Construction | 2026 |
| First Rail Wales and Western Holdings Limited | Transport & logistics | 2023 |
| First Rail Wales and Western Limited | Transport & logistics | 2023 |
| First Rate Properties Limited | Real estate | 2024 |
| First Response Tyres Ltd | Manufacturing | 2025 |
| Fisher Industrial Rubber Limited | Wholesale & retail | 1991 |
| Fit and Fresh Ltd | Hospitality | 2024 |
| Fitness UN Limited | Extraterritorial | 2013 |
| Fitnesshealth Ltd | Wholesale & retail | 2013 |
| Fitt Bake Limited | Hospitality | 2018 |
| Fitter Body Ladies Hendy Ltd | Arts & recreation | 2024 |
| Fitter Body Ladies Pontardawe Ltd | Arts & recreation | 2023 |
| Fitzhamon Embankment Management Limited | Households | 2009 |
| Five Bondhu Ltd | Hospitality | 2024 |
| Five Elements Academy Ltd | Education | 2022 |
| Five Maples Limited | Financial services | 2020 |
| Fiverzswansea Limited | Hospitality | 2025 |
| FIX My Spine Limited | Health & social care | 2015 |
| Fixit Cleaners Ltd | Construction | 2024 |
| Fixmar Ltd | Manufacturing | 2017 |
| Fixxon Limited | Manufacturing | 2013 |
| Fiya Creative CIC | Arts & recreation | 2025 |
| FK & More Limited | Construction | 2012 |
| FL Carpentry Ltd | Manufacturing | 2023 |