| Conaghan PUB Group Ltd | Hospitality | 2025 |
| Concept Services Groupe Limited | Transport & logistics | 2026 |
| Concrete Creative Design Consultants Limited | Professional & scientific | 2017 |
| Concrexion Ltd | Construction | 2026 |
| Condado Medical Services Ltd | Health & social care | 2019 |
| Condrache Valentin Plastering Ltd | Construction | 2018 |
| Conexion Properties Ltd | Real estate | 2022 |
| Coniston Thistle Consulting Ltd | Information & communication | 2025 |
| Connell Drummond Holdings Ltd | Arts & recreation | 2022 |
| Connexer Limited | Administrative & support | 2023 |
| Connor Wilson Rail Services Ltd | Construction | 2016 |
| Conord-Pt Ltd | Health & social care | 2022 |
| Contact CD Limited | Information & communication | 2006 |
| Container Depot Limited | Administrative & support | 2020 |
| Continental Cross Coffee Ltd | Wholesale & retail | 2025 |
| Contour Events Ltd | Arts & recreation | 2020 |
| Controlled Technical Services Ltd | Wholesale & retail | 2025 |
| Conway Properties (Scotland) Limited | Real estate | 2011 |
| Coopella Ltd | Real estate | 2026 |
| Cooper Decorators Limited | Construction | 2020 |
| Coorie Lodge Limited | Hospitality | 2019 |
| Coorie Renovations Ltd | Construction | 2019 |
| Core Property Group (Ayrshire) Limited | Construction | 2024 |
| Core Systems Holdings Limited | Financial services | 2022 |
| Core Timber Systems Limited | Manufacturing | 2019 |
| Corrigandickestates Ltd | Households | 2025 |
| Corrine Smith Design Ltd | Manufacturing | 2015 |
| Corsehouse Commercials Limited | Manufacturing | 2004 |
| Cortex Physiotherapy Ltd | Health & social care | 2023 |
| Cottage 828 Limited | Hospitality | 2025 |
| Cottage Catering (Kilmarnock) Limited | Hospitality | 2012 |
| Coughtrie Catering Limited | Hospitality | 2019 |
| Coughtrie Holdings Limited | Financial services | 2019 |
| Council of Voluntary Organisations (East Ayrshire) Limited | Other services | 2003 |
| Courtney Cassidy Aesthetics Ltd | Other services | 2021 |
| Cowan & Davidson (Joiners & Builders) Limited | Construction | 2003 |
| Cowie Physiotherapy Limited | Health & social care | 2021 |
| CP (Electric) Limited | Wholesale & retail | 2017 |
| CP (Electric) Management Services Ltd | Administrative & support | 2023 |
| Cpsonline Limited | Wholesale & retail | 2022 |
| Crackin Events Limited | Hospitality | 2019 |
| Craft Daft Limited | Arts & recreation | 2015 |
| Craig Bilham Executive Travel Limited | Administrative & support | 2016 |
| Craig Brown Music Limited | Information & communication | 2011 |
| Craig Mcclintock Heating Limited | Construction | 2022 |
| Craig Roberts Interiors Limited | Other services | 2023 |
| Craigewan Property Limited | Real estate | 2008 |
| Craigie Carehome Ltd | Health & social care | 2022 |
| Craigie Mill Limited | Households | 2016 |
| Craigie Property Investments Ltd. | Real estate | 2012 |
| Craigie Road Motors Ltd | Wholesale & retail | 2017 |
| Cranworths Limited | Construction | 2024 |
| Craufurdland Limited | Agriculture & fishing | 1996 |
| Create Communications LLP | | 2008 |
| Create Without Limits Limited | Health & social care | 2019 |
| Creative Designs (AYR) Limited | Administrative & support | 1988 |
| Creative Designs Contracts Limited | Administrative & support | 2017 |
| Creative Goose Ltd | Arts & recreation | 2025 |
| Creative Jobs Board Ltd | Professional & scientific | 2017 |
| Creative Landscapes (Scotland) Ltd. | Administrative & support | 2012 |
| Credalgo Ltd | Information & communication | 2020 |
| Creebridge Mill Limited | Wholesale & retail | 2014 |
| Crew Building & Maintenance Limited | Construction | 2024 |
| Croia Medispa Ltd | Other services | 2023 |
| Crosshouse Action NOW Community Company Ltd | Arts & recreation | 2013 |
| Crosshouse Valeting Ltd | Administrative & support | 2020 |
| Crosshousepols Ltd | Wholesale & retail | 2018 |
| Crossroads Community Hub Ltd. | Hospitality | 2011 |
| Crown Chemicals Limited | Wholesale & retail | 2005 |
| Crown Recruitment & Locum Services Ltd | Administrative & support | 2020 |
| Cruinne Limited | Professional & scientific | 2015 |
| CSD Properties (Ayrshire) Ltd | Real estate | 2023 |
| CT SAM Limited | Professional & scientific | 2007 |
| CTR Property Ltd | Real estate | 2018 |
| Culzean Consultancy Ltd | Professional & scientific | 2025 |
| Cunningham Logistics Ltd | Transport & logistics | 2025 |
| Cuppakapi Limited | Hospitality | 2018 |
| Curated Media Ltd | Information & communication | 2012 |
| Curated Property Portfolio Ltd | Real estate | 2025 |
| Current Works Consultancy Limited | Construction | 2020 |
| Custody & Offender Medical Services LLP | | 2014 |
| Custom Kits Limited | Manufacturing | 2018 |
| Cutwood Joinery Ltd | Construction | 2023 |
| CWJ Design Services Ltd | Professional & scientific | 2026 |
| CY Property Holdings Ltd | Financial services | 2026 |
| CY Property Ltd | Real estate | 2022 |
| D & D Decorators Limited | Construction | 2015 |
| D & S Norrington Properties Ltd | Real estate | 2017 |
| D & W Consultancy Ltd | Health & social care | 2019 |
| D - Minor Ltd | Wholesale & retail | 2022 |
| D a Dunlop Ltd | Manufacturing | 2022 |
| D Brodie Surveying & Cost Consultants Ltd | Construction | 2023 |
| D Devlin Kitchens Ltd | Construction | 2021 |
| D H Maxwell Ltd | Professional & scientific | 2025 |
| D I a Enterprises Ltd | Wholesale & retail | 2016 |
| D M Homeshield Ltd | Construction | 2012 |
| D Millar Plumbing, Heating & GAS Limited | Construction | 2021 |
| D.B Aero Engineering Ltd | Manufacturing | 2026 |
| D.Gorman Joinery & Home Services Ltd | Construction | 2026 |
| D4 Sparkle & Shine Services Ltd | Administrative & support | 2026 |