- RICHARD O'SULLIVAN LIMITEDDissolved- 04750966 - Dissolved on 28 May 2013 
- BRENDAN O'SULLIVAN LIMITEDActive - Proposal to Strike off- 07402865 - Incorporated on 11 October 2010 
- O'SULLIVAN SYSTEMS LIMITEDDissolved- 09472804 - Dissolved on 13 August 2019 
- CHRISTINA O'SULLIVAN LIMITEDActive - Proposal to Strike off- 06572839 - Incorporated on 22 April 2008 
- KATE O'SULLIVAN LIMITED- 04376020 - Incorporated on 18 February 2002 
- NEIL O'SULLIVAN LTDLiquidation- 06211487 - Incorporated on 13 April 2007 
- SEAN O'SULLIVAN LIMITEDActive - Proposal to Strike off- 08652112 - Incorporated on 15 August 2013 
- O'SULLIVAN PROPERTIES LIMITED- 07783351 - Incorporated on 22 September 2011 
- DARREN O'SULLIVAN LTDDisolved- 12155011 - Dissolved on 30 November 2021 
- O'SULLIVAN SERVICES LIMITED- 11454192 - Incorporated on 9 July 2018 
- O'SULLIVAN MEDICAL LTDDisolved- 10900858 - Dissolved on 31 October 2023 
- O'SULLIVAN ESTATE LIMITEDDisolved- 10970063 - Dissolved on 1 August 2023 
- O'SULLIVAN LOGISTICS LIMITED- 09938083 - Incorporated on 6 January 2016 
- O'SULLIVAN ENGINEERING LIMITEDActive - Proposal to Strike off- 10279451 - Incorporated on 14 July 2016 
- O'SULLIVAN BUILDERS LTDActive - Proposal to Strike off- 10276951 - Incorporated on 13 July 2016 
- MARIA O'SULLIVAN LLP- OC429963 - Incorporated on 10 December 2019 
- O'SULLIVAN HIGHWAYS LTDDisolved- 13849943 - Dissolved on 13 December 2022 
- O'SULLIVAN ROOFING LTD- 13942903 - Incorporated on 27 February 2022 
- O'SULLIVAN ASSETS LIMITED- 15863760 - Incorporated on 29 July 2024 
- O'SULLIVAN DAVIES LTD- 16213838 - Incorporated on 28 January 2025