| Ground Truth Forestry Ltd | Agriculture & fishing | 2025 |
| GROUP369 Ltd | Construction | 2025 |
| GRW Scout Ltd | Information & communication | 2025 |
| GRW Talent Ltd | Administrative & support | 2025 |
| GS Gillies Ltd | Transport & logistics | 2024 |
| GS Plumbing Heating & GAS Ltd | Construction | 2018 |
| GS Shoes Ltd. | Wholesale & retail | 2011 |
| GSC Letting Ltd | Real estate | 2019 |
| GSC Shawlands Ltd | Health & social care | 2025 |
| Gsfm Facilities Management Limited | Administrative & support | 2023 |
| GSR Aviation Limited | Transport & logistics | 2010 |
| GT Autos (AYR) Limited | Wholesale & retail | 2022 |
| GT Logistical Services Ltd | Transport & logistics | 2025 |
| GTR Joinery Limited | Manufacturing | 2022 |
| Guardian Fire & Security Limited | Administrative & support | 2017 |
| Gusbo Investments Ltd | Health & social care | 2024 |
| GUY Chalmers Rigging Ltd | Mining & quarrying | 2015 |
| Guyz Barbers Condorrat Limited | Wholesale & retail | 2013 |
| GWB2000 Ltd | Hospitality | 2024 |
| GWC Lifting Operations Ltd | Construction | 2025 |
| H & M Scaffolding Limited | Construction | 2016 |
| H&Aa Consultancy Ltd | Professional & scientific | 2023 |
| H&R Milestone Property Ltd | Real estate | 2022 |
| Hacsm Limited | Professional & scientific | 2016 |
| Hafsa AYR Ltd | Hospitality | 2025 |
| Hafsa Food Limited | Hospitality | 2026 |
| Hair Spot (Ayrshire) Ltd | Other services | 2026 |
| Hairanagen Ltd | Health & social care | 2013 |
| Hairstopper Limited | Other services | 2005 |
| Hallburn Construction & Joinery Ltd | Construction | 2025 |
| Halligan Murray Consultants Limited | Professional & scientific | 2024 |
| Hamilton Assetz Ltd | Real estate | 2019 |
| Hamilton Foods (AYR) Ltd | Wholesale & retail | 2022 |
| Hamilton Haulage Limited | Transport & logistics | 2014 |
| Hamish Simpson Ltd | Health & social care | 2021 |
| Hannah Wealth Management Limited | Professional & scientific | 2019 |
| Happy Heroes Limited | Health & social care | 2022 |
| Happyvaluables Ltd | Wholesale & retail | 2024 |
| Harbour 10 Limited | Other services | 2012 |
| Harbour 2022 Limited | Hospitality | 2022 |
| Harelaw Trout Fishery Ltd | Agriculture & fishing | 2021 |
| Harizma Alliance LP | | 2014 |
| Harkness Ltd | Hospitality | 2020 |
| Harling Investments Limited | Financial services | 2023 |
| Harrington Productions Limited | Administrative & support | 2009 |
| Harrison AYR Ltd | Hospitality | 2023 |
| Hart Property & Lettings Ltd | Construction | 2021 |
| Hartfield House (AYR) Ltd | Real estate | 2012 |
| Harvey Mclean Limited | Manufacturing | 1992 |
| Hassaan Ltd | Hospitality | 2022 |
| Hatch CS Ltd | Professional & scientific | 2017 |
| HATS4HEATHENS Ltd | Wholesale & retail | 2023 |
| Havanna Properties Ltd | Real estate | 2021 |
| Hawkhill Capital Ltd | Real estate | 2023 |
| Hayway Joinery Limited | Construction | 2011 |
| Hayway Property Development Ltd | Real estate | 2020 |
| Hazsol Environmental Limited | Water & waste | 2024 |
| Head in the Skye Ltd | Real estate | 2020 |
| Heads of AYR Farm Park (Scotland) Ltd | Arts & recreation | 2014 |
| Heads of AYR Nursery Ltd | Health & social care | 2018 |
| Headway Ayrshire | Other services | 1997 |
| Hearth - the Heart of the Earth CIC | Education | 2025 |
| Heartstart Ayrshire and Arran | Health & social care | 1995 |
| Heat-Ayr Ltd | Construction | 2011 |
| Heatayr GAS Services Ltd | Construction | 2025 |
| Heather Hill Ventures Ltd | Hospitality | 2026 |
| Heatherhyll Properties Limited | Real estate | 2026 |
| Heatherstone Investments Ltd | Real estate | 2020 |
| Heavenly Treats Parlor Limited | Hospitality | 2025 |
| HEG Holdings Limited | Energy | 2018 |
| Height Evac Limited | Professional & scientific | 2018 |
| Helix Homes Ltd | Construction | 2018 |
| Hemin Abdulla Ltd | Wholesale & retail | 2024 |
| Henderson Carpets Limited | Construction | 2020 |
| Hendl Distribution Ltd | Wholesale & retail | 2024 |
| Hendry Developments Limited | Construction | 1990 |
| Heritage and Design Limited | Professional & scientific | 2005 |
| Heritage Property Group (AYR) Ltd | Real estate | 2025 |
| Hesper Ventures LP | | 2013 |
| Hetleys (UK) Ltd | Wholesale & retail | 2010 |
| HG Pyper Ltd. | Wholesale & retail | 2013 |
| HH Springside Limited | Real estate | 2025 |
| HI Social Ltd | Professional & scientific | 2020 |
| Hidden Treasures (AYR) Limited | Wholesale & retail | 2012 |
| High Life Travel Limited | Administrative & support | 2016 |
| High Street Gadgets Ltd | Wholesale & retail | 2026 |
| Highford Homes Limited | Real estate | 2023 |
| Highland Estate Care Ltd | Real estate | 2024 |
| Highstreet Convenience Store Limited | Wholesale & retail | 2025 |
| Hill Top Saws Ltd | Manufacturing | 2021 |
| Hillfoot Chippy Ltd | Hospitality | 2026 |
| Hillfort Contracts Limited | Construction | 2023 |
| Hillspire Property Ltd | Real estate | 2024 |
| HIS Grooming Ltd | Other services | 2025 |
| Hmac Ltd | Hospitality | 2013 |
| HMC Makeup Studios Ltd | Real estate | 2019 |
| HMS (Scotland) Limited | Administrative & support | 2006 |
| HNS 104 Ltd | Hospitality | 2023 |
| Hollybrook Lodge Ltd | Real estate | 2024 |
| Hollybrook.Xyz Limited | Wholesale & retail | 2018 |