- O'SULLIVAN 1960 LIMITEDActive - Proposal to Strike off- 08862002 - Incorporated on 27 January 2014 
- KEIRON O'SULLIVAN LIMITED- 09053064 - Incorporated on 22 May 2014 
- O'SULLIVAN FUTURES LIMITED- 09799910 - Incorporated on 29 September 2015 
- IAN O'SULLIVAN LIMITED- 09826254 - Incorporated on 15 October 2015 
- O'SULLIVAN BMS LIMITEDActive - Proposal to Strike off- 11324897 - Incorporated on 24 April 2018 
- DPM O'SULLIVAN LIMITEDDisolved- 11889336 - Dissolved on 17 August 2021 
- CALLUM O'SULLIVAN LTDDisolved- 11862433 - Dissolved on 8 August 2023 
- O'SULLIVAN MACFARLANE LTD- NI639239 - Incorporated on 21 June 2016 
- O'SULLIVAN HOMES LIMITED- 12074084 - Incorporated on 28 June 2019 
- O'SULLIVAN IT LTD- 11231835 - Incorporated on 5 March 2018 
- EVE O'SULLIVAN LIMITEDDissolved- 10215073 - Dissolved on 16 October 2018 
- CIAN O'SULLIVAN LIMITEDDisolved- 13382357 - Dissolved on 27 May 2025 
- OWEN O'SULLIVAN LIMITED- 14303762 - Incorporated on 18 August 2022 
- O'SULLIVAN ESTATES LTD- 15072852 - Incorporated on 15 August 2023 
- O'SULLIVAN TM LTDActive - Proposal to Strike off- 15706516 - Incorporated on 7 May 2024 
- O'SULLIVAN MOTORS LIMITEDDisolved- 16233291 - Dissolved on 24 June 2025 
- SMITH & O'SULLIVAN LIMITEDDisolved- 01394213 - Dissolved on 18 May 2025 
- ANDREW O'SULLIVAN LTD- 04380221 - Incorporated on 22 February 2002 
- MACPHERSON O'SULLIVAN LLPDissolved- OC304858 - Dissolved on 4 August 2009 
- O'SULLIVAN SOLUTIONS LTD- 08037732 - Incorporated on 19 April 2012