| Llandaff City Busy Bees Ltd | Education | 2015 |
| Llandaff Engineering Company Limited | Manufacturing | 1964 |
| Llandaff Investments Limited | Real estate | 1963 |
| Llandaff Market Ltd | Wholesale & retail | 2025 |
| Llandaff North Gospel Hall | Other services | 2005 |
| Llandaff North Rugby, Sports and Social Club Ltd. | Arts & recreation | 2012 |
| Llandaff Place Limited | Real estate | 2011 |
| Llandaff Place Management Company Limited | Households | 2015 |
| Llandaff Property Investments Limited | Real estate | 2008 |
| Llandaff RFC Limited | Arts & recreation | 2019 |
| Llandaff Shop Ltd | Wholesale & retail | 2025 |
| Llandennis Court Management Company Limited | Households | 2000 |
| Llandennis Road Trading Ltd | Wholesale & retail | 2024 |
| Llandinam Developers Limited | Construction | 1993 |
| Llanedeyrn Fish Bar Limited | Hospitality | 2024 |
| Llanfair Court Investments Limited | Real estate | 1955 |
| Llangoed Healthcare Ltd | Health & social care | 2022 |
| Llangoelan Medical CYF | Health & social care | 2022 |
| Llanilltern Apartments RMC Ltd | Households | 2021 |
| Llanilltern Village RMC Ltd | Households | 2019 |
| Llanishen Court Development Limited | Households | 1973 |
| Llanishen Garage (Cardiff) Ltd | Wholesale & retail | 2012 |
| Llanishen Garage Holdings Limited | Financial services | 2022 |
| Llanishen Healthcare Limited | Health & social care | 2001 |
| Llanishen MOT and Service Centre Limited | Wholesale & retail | 2012 |
| Llanishen Rugby & Pitch Hire Limited | Administrative & support | 2018 |
| Llanishen Rugby & Social Club Limited | Hospitality | 2011 |
| Llanishen Stores Ltd | Wholesale & retail | 2023 |
| Llanllyr Water Company Limited | Manufacturing | 1998 |
| Llanover HSE Consultancy Ltd | Professional & scientific | 2020 |
| Llanrumney Chippy Ltd | Hospitality | 2025 |
| Llanrumney Community Forum | Other services | 2008 |
| Llanrumney Food Stores Limited | Wholesale & retail | 2014 |
| Llanrumney Hall Community Trust Limited | Arts & recreation | 2015 |
| Llanrumney Spice Ltd | Hospitality | 2023 |
| Llanrumney Top Hand Car Wash Ltd | Administrative & support | 2025 |
| Llantarnam Care Limited | Health & social care | 2011 |
| Llantrisant Landscapes Company Ltd | Administrative & support | 2025 |
| Llantwit Street Ltd | Real estate | 2021 |
| Llanyrafon Dental Practice Limited | Health & social care | 2005 |
| Llawen Holiday Cottages Limited | Real estate | 2022 |
| Llawnroc Care Ltd | Health & social care | 2024 |
| LLB Electrical Ltd | Construction | 2019 |
| LLC Zkmt Limited | Wholesale & retail | 2024 |
| Llcs Construction Limited | Construction | 2025 |
| Llechen LAN CYF. | Information & communication | 2010 |
| Llensarms Limited | Financial services | 2008 |
| Lleshi Builders Ltd | Construction | 2019 |
| Lletai Siriol CYF. | Real estate | 2021 |
| Llew Medical Ltd | Health & social care | 2022 |
| Llewellyn Consultancy Ltd | Professional & scientific | 2015 |
| Llewellyn Developments Ltd | Construction | 2019 |
| Llewellyn Financial Solutions Ltd | Financial services | 2004 |
| Llewellyn Investments Ltd | Real estate | 2022 |
| Llewellyn Lettings Ltd | Real estate | 2025 |
| Llewellyn Management Ltd | Households | 2024 |
| Llewellyns Financial Limited | Financial services | 2020 |
| Llewellyns Group Limited | Financial services | 2025 |
| Llewelyn Gray Consulting Ltd | Professional & scientific | 2023 |
| LLG International | Administrative & support | 2026 |
| Llgf Ltd | Wholesale & retail | 2021 |
| LLH Beauty Ltd | Other services | 2025 |
| Llizard Ltd | Financial services | 2021 |
| LLK (Kent) Ltd | Administrative & support | 2017 |
| Llkm Ltd | Professional & scientific | 2025 |
| LLL Wellness Club Ltd | Hospitality | 2024 |
| Lloci Limited | Wholesale & retail | 2025 |
| Lloyd Anderson Limited | Financial services | 2001 |
| Lloyd Bell Productions Ltd | Information & communication | 2004 |
| Lloyd Construction Services Limited | Professional & scientific | 2025 |
| Lloyd Electrical Contractors Limited | Construction | 2017 |
| Lloyd Griffiths Hair Salons Limited | Other services | 2015 |
| Lloyd International Corporation Ltd | Wholesale & retail | 2017 |
| Lloyd-Enrichment Ltd | Professional & scientific | 2017 |
| Lloydlie Lets Limited | Real estate | 2023 |
| Lloyds Bakery Limited | Manufacturing | 2025 |
| Lloyds Contracts Limited | Construction | 2009 |
| Lloyds MOT Centre Ltd | Wholesale & retail | 2016 |
| LLS Construction Limited | Construction | 2025 |
| LLS Stores Limited | Wholesale & retail | 2022 |
| Llusern Scientific Ltd | Professional & scientific | 2020 |
| LLW Construction and Carpentry Ltd | Construction | 2024 |
| Llwybr Papur /Papertrail CYF | Arts & recreation | 2014 |
| Llwyddo CYF. | Education | 2023 |
| Llwynbrain Alpacas Limited | Agriculture & fishing | 2023 |
| Llyn International Ltd | Extraterritorial | 2017 |
| Llyn Lort Energy Park Limited | Energy | 2021 |
| Llyn Lort II Energy Park Limited | Energy | 2022 |
| Llys Pegasus RTM Company Limited | Households | 2020 |
| Llysfaen Consulting Ltd | Administrative & support | 2021 |
| Llysywaun Limited | Health & social care | 2003 |
| LM Gordinho Limited | Construction | 2016 |
| LM Traffic Management Limited | Construction | 2017 |
| Lmaca Tech SP Limited | Wholesale & retail | 2025 |
| Lmah Limited | Health & social care | 2019 |
| Lmap Holdings Limited | Financial services | 2024 |
| Lmap Limited | Financial services | 2013 |
| Lmates Limited | Health & social care | 2021 |
| LMB Management NW Ltd | Professional & scientific | 2019 |
| LMB Pubs Ltd | Hospitality | 2025 |