| Blink Vivid Ltd | Information & communication | 2020 |
| Blisco Ltd | Real estate | 1997 |
| Bliss and Zest Apartments Limited | Hospitality | 2019 |
| Bliss Booth Ltd | Professional & scientific | 2026 |
| Bliss Homes Development Limited | Construction | 2019 |
| Bliss Investment Properties Limited | Real estate | 2019 |
| Bliss Sinama Limited | Professional & scientific | 2023 |
| Blissful Retreats Ltd | Real estate | 2023 |
| Blitz Real Estate Limited | Real estate | 2025 |
| Blkyan Property Limited | Real estate | 2024 |
| Blms Consulting Limited | Professional & scientific | 2016 |
| Bloc Enterprise Ltd | Other services | 2022 |
| Bloc Studios Limited | Arts & recreation | 2009 |
| Block and Brick Property Ltd | Real estate | 2025 |
| Blockcloud Computing Ltd | Professional & scientific | 2026 |
| Blocklab Studios Ltd | Information & communication | 2018 |
| Blockpool Limited | Information & communication | 2016 |
| Blocks of Flats for Sale Ltd | Real estate | 2024 |
| Blockshop Limited | Manufacturing | 1984 |
| Blocpharma Limited | Wholesale & retail | 2025 |
| Blokka Ltd | Construction | 2014 |
| Blood Line Properties Limited | Real estate | 2023 |
| Blood Metrics Ltd | Health & social care | 2024 |
| Blood, Sweat & Beers Limited | Hospitality | 2006 |
| Blooj Ltd | Real estate | 2018 |
| Bloom Hair Salon Limited | Other services | 2015 |
| Bloom Sheffield CIC | Agriculture & fishing | 2020 |
| Bloombizz Ltd | Information & communication | 2026 |
| Bloomelle Limited | Administrative & support | 2024 |
| Blooming Butterflies Ltd | Health & social care | 2025 |
| Bloomwell Housing Ltd | Health & social care | 2026 |
| Blossom Learning Tree Ltd | Health & social care | 2022 |
| Blossom & Believe Ltd | Professional & scientific | 2025 |
| Blossom & Branch Hospitality Ltd | Hospitality | 2025 |
| Blossom Day Opportunities Sheffield Limited | Health & social care | 2020 |
| Blossom Fish Limited | Administrative & support | 2024 |
| Blossom Spa & Nails Ltd | Other services | 2023 |
| Blossom Tree (Bentley) Ltd | Health & social care | 2025 |
| Blossom Tree Bloomers Ltd | Health & social care | 2025 |
| Blossom Tree Ladybugs Ltd | Health & social care | 2026 |
| Blossom Tree Nails Limited | Other services | 2018 |
| Blossom Tree Nursery Limited | Health & social care | 2020 |
| Blossom Tree Nursery Mexborough Ltd | Health & social care | 2024 |
| Blossom Tree Woodlands Nursery Ltd | Health & social care | 2026 |
| Blossom View Respite Unit Ltd | Health & social care | 2018 |
| Blossom Wellbeing Group Limited | Financial services | 2014 |
| Blossomgate L Limited | Health & social care | 2025 |
| Blossomgater Ltd | Education | 2025 |
| Blossoms Estate Agents Ltd | Real estate | 2026 |
| Blow & Scrimshaw Limited | Water & waste | 1964 |
| Blowout Promotions Ltd | Hospitality | 2025 |
| Blowout Youth CIC | Arts & recreation | 2025 |
| Blox Construction Ltd | Construction | 2018 |
| Blox Property Developments Limited | Construction | 2023 |
| Bloxburg Construction Ltd | Construction | 2018 |
| BLR Construction Limited | Construction | 2018 |
| BLR Electrical Ltd | Construction | 2018 |
| Blsd Solutions Limited | Health & social care | 2015 |
| BLU Gekko Limited | Manufacturing | 2020 |
| BLU Paper Clip Limited | Construction | 2017 |
| Blue and Well Ltd | Wholesale & retail | 2024 |
| Blue Axis Ltd | Professional & scientific | 2025 |
| Blue Beaver Ltd | Wholesale & retail | 2005 |
| Blue BEE Brewery Ltd | Manufacturing | 2010 |
| Blue Bell PUB and Restaurants Limited | Hospitality | 2022 |
| Blue Blood Properties Ltd | Construction | 2018 |
| Blue Box Storage (Sheffield) Limited | Other services | 2023 |
| Blue Brick Concrete & Aggregates Limited | Manufacturing | 2017 |
| Blue Brik Properties Limited | Administrative & support | 2017 |
| Blue Chula Ltd | Professional & scientific | 2017 |
| Blue Consulting Solutions Limited | Information & communication | 2003 |
| Blue Coral Healthcare Ltd | Health & social care | 2022 |
| Blue Gold Vintage Limited | Wholesale & retail | 2015 |
| Blue Island Limited | Extraterritorial | 2025 |
| Blue Kangaroo Consultancy Limited | Administrative & support | 2009 |
| Blue Light Safety Holdings Limited | Financial services | 2018 |
| Blue Light Safety Limited | Professional & scientific | 2012 |
| Blue Limes Limited | Hospitality | 1999 |
| Blue Marine Systems Ltd | Wholesale & retail | 2012 |
| Blue Moon Hospitality Management Services Limited | Hospitality | 2018 |
| Blue Nile Sheff Ltd | Wholesale & retail | 2026 |
| Blue Ocean Aquatics Limited | Transport & logistics | 2009 |
| Blue One Developments Limited | Construction | 2024 |
| Blue One Group Limited | Financial services | 2023 |
| Blue One Properties Limited | Real estate | 2017 |
| Blue One Serviced Apartments Limited | Hospitality | 2026 |
| Blue Path Support Services Limited | Administrative & support | 2025 |
| Blue Portal Holdings Limited | Professional & scientific | 2012 |
| Blue Portal IT Ltd | Information & communication | 2018 |
| Blue Portal Telecom Limited | Information & communication | 2003 |
| Blue Sky Assets Limited | Real estate | 2014 |
| Blue Sky Broadcast Ltd | Information & communication | 2023 |
| Blue Sky Interactive Limited | Professional & scientific | 2002 |
| Blue Sky IT Solutions Limited | Information & communication | 2004 |
| Blue Stand Table Ltd | Information & communication | 2024 |
| Blue Stone Properties (Hallam) Limited | Real estate | 2018 |
| Blue Strawberry Elephant Limited | Administrative & support | 2006 |
| Blue Strawberry Properties Ltd | Real estate | 2024 |
| Blue Team Solutions Ltd | Information & communication | 2024 |
| Blue Top Financial Services Limited | Professional & scientific | 2019 |