| Brass Monkey Saltburn Ltd | Wholesale & retail | 2024 |
| Briblesbakes Limited | Wholesale & retail | 2026 |
| Brockley Hall Limited | Hospitality | 2019 |
| Brotton Seafoods Limited | Wholesale & retail | 2024 |
| Brownmore Investments Ltd | Construction | 2019 |
| Browns Plumbing Whitby Ltd | Construction | 2023 |
| BSS Heating Heroes Ltd | Construction | 2025 |
| BT Groundworks Limited | Financial services | 2025 |
| Buttercup Coffee House Limited | Hospitality | 2025 |
| BW Online (Yorkshire) Ltd | Arts & recreation | 2024 |
| Bwell Ltd | Health & social care | 2017 |
| C & DT Property Limited | Households | 2018 |
| C&J Engineering Services Limited | Professional & scientific | 2023 |
| C.A.R Properties Limited | Real estate | 2019 |
| Cabloc Ltd | Administrative & support | 2016 |
| Cafe Creations 2 Go Ltd | Hospitality | 2023 |
| Calderbank Property Group Limited | Real estate | 2025 |
| Cambrian Creels Ltd. | Manufacturing | 2014 |
| Camfields Espresso Bar Limited | Hospitality | 2012 |
| Camrob Developments Limited | Construction | 2025 |
| Capability Delivery Services Limited | Professional & scientific | 2021 |
| Capacity Minerals Ltd | Mining & quarrying | 2025 |
| Caroline Paddle Cyber Solutions Limited | Information & communication | 2020 |
| Cartech SVS Ltd | Wholesale & retail | 2021 |
| Cath's Raku Pottery Ltd | Arts & recreation | 2025 |
| Cato Design Limited | Professional & scientific | 2008 |
| Cattersty Limited | Professional & scientific | 2019 |
| CEA Safety Solutions Ltd | Professional & scientific | 2022 |
| Champion Contract Services (North East) Limited | Mining & quarrying | 2017 |
| Champions Plumbing & Heating Limited | Construction | 2019 |
| Charisma Joinery Ltd | Construction | 2000 |
| Chemastic Ltd | Other services | 2013 |
| Chocolini's Ltd | Manufacturing | 2021 |
| Chris Birkbeck Rallyschool Limited | Arts & recreation | 2022 |
| Chris Malbon Limited | Construction | 2013 |
| Chris Parker Limited | Wholesale & retail | 2003 |
| Christopher Vasey Logistics Ltd | Transport & logistics | 2025 |
| Chrystal Clear Housing Ltd | Construction | 2021 |
| City of Ironopolis Limited | Extraterritorial | 2006 |
| CJC Consulting Ltd | Professional & scientific | 2024 |
| Clacherty's Ltd | Real estate | 2023 |
| Clachertys Holdings Ltd | Other services | 2025 |
| Claire House (Saltburn) Ltd | Hospitality | 1995 |
| Classic Brocante Ltd | Wholesale & retail | 2012 |
| CLE Consultants Ltd | Professional & scientific | 2025 |
| Clean Green Recycling Ltd | Water & waste | 2014 |
| Cleveland Ironstone Mining Museum | Education | 1999 |
| Cleveland Legionnaire Management Limited | Households | 2015 |
| Cleveland Potash Pension Trustees Limited | Administrative & support | 1974 |
| Cliffden Court Management Company Limited | Households | 1983 |
| Clover Hill Scaling Ltd | Hospitality | 2021 |
| Coast to Country Holidays & Accommodation Limited | Real estate | 2024 |
| Coaten Property Limited | Real estate | 2019 |
| COD Head Brewing Company Ltd | Manufacturing | 2023 |
| Coffee @ Yle's Ltd | Hospitality | 2021 |
| Collins Property NW Limited | Real estate | 2018 |
| Construction Scaffolding Limited | Construction | 1999 |
| Continue Technology Limited | Wholesale & retail | 2018 |
| Conveyancing Search Company Limited | Professional & scientific | 2026 |
| Cooper Care Consultancy Ltd | Health & social care | 2019 |
| Coral House (Saltburn) Management Company Limited | Real estate | 2008 |
| Covert Pest Solutions Ltd | Wholesale & retail | 2023 |
| Cowell Estates Ltd | Real estate | 2023 |
| Crazy Price Carpets (Skelton) Limited | Construction | 2024 |
| Creation Saltburn Ltd | Arts & recreation | 2023 |
| CT Engineering Services Ltd | Manufacturing | 2025 |
| Cyberpt Limited | Health & social care | 2022 |
| D & R Cutting & Dismantling Ltd | Construction | 2011 |
| D M Bird Limited | Construction | 2017 |
| D W Gill Electrical Contractors Ltd | Construction | 2011 |
| D Wood Properties Limited | Real estate | 2018 |
| D&N Reinforcements Ltd | Construction | 2016 |
| D. J. C. Restoration Limited | Manufacturing | 2020 |
| D. J. Wood Limited | Mining & quarrying | 2016 |
| D.J. Commercials Limited | Manufacturing | 2002 |
| Daisy Distillery Limited | Manufacturing | 2018 |
| Dalcal Property Limited | Real estate | 2019 |
| Davey Todd Ltd | Arts & recreation | 2019 |
| Day One Motorsport Ltd | Professional & scientific | 2025 |
| DC Mobility (G) Ltd | Health & social care | 2019 |
| DE Brus Court Company Limited | Households | 1986 |
| Design My Gym Limited | Professional & scientific | 2022 |
| DH Auto Upholstery Ltd | Other services | 2022 |
| Dicken's Saltburn Limited | Health & social care | 2011 |
| DIG IT Projects Franchising Limited | Wholesale & retail | 2010 |
| Digger Doctor (NE) Ltd | Manufacturing | 2018 |
| Dimbur Services Ltd | Professional & scientific | 2013 |
| DJ Roadworks Limited | Construction | 2025 |
| DM Data (NE) Limited | Professional & scientific | 2016 |
| Dmadd Ltd | Professional & scientific | 2014 |
| DMG Food Safety Solutions Ltd | Education | 2014 |
| DMS Top House Ltd | Hospitality | 2024 |
| DMT Mechanical Services Ltd | Manufacturing | 2017 |
| Donhill Contract Carpenters Limited | Manufacturing | 2009 |
| Doodicious Enterprises Limited | Information & communication | 2026 |
| DP Bistro Services Ltd | Hospitality | 2018 |
| DP Holiday Lets Limited | Real estate | 2020 |
| DS Luxe Home Interiors Limited | Construction | 2024 |
| DSR Electrics Ltd | Construction | 2020 |
| DT ENG Design Ltd | Professional & scientific | 2023 |