- O'NEILL INDUSTRIAL LIMITEDActive - Proposal to Strike off- 10134994 - Incorporated on 20 April 2016 
- NIAMH O'NEILL LIMITEDActive - Proposal to Strike off- 10292924 - Incorporated on 25 July 2016 
- MIKE O'NEILL LIMITEDActive - Proposal to Strike off- 10339885 - Incorporated on 22 August 2016 
- MCGRATH & O'NEILL LTDLiquidation- 10350089 - Incorporated on 27 August 2016 
- O'NEILL ACCOUNTANCY LIMITED- 10367150 - Incorporated on 9 September 2016 
- O'NEILL & HOLMAN LIMITED- 10416516 - Incorporated on 7 October 2016 
- O'NEILL CONTRACTORS LTDDisolved- 13652027 - Dissolved on 3 June 2025 
- O'NEILL & MCPOLIN LLP- NC001812 - Incorporated on 19 March 2025 
- O'NEILL ROOFING AND CHERRYPICKER HIRE LTD- SC669344 - Incorporated on 30 July 2020 
- MEET SEAN O'NEILL LTD- 14456267 - Incorporated on 1 November 2022 
- LIAM O'NEILL GOLF LTD- 13131551 - Incorporated on 13 January 2021 
- NEILL MK SHOPES LTDDisolved- 14715874 - Dissolved on 13 August 2024 
- A. O'NEILL & SON LIMITED- 07972620 - Incorporated on 1 March 2012 
- DLK O NEILL LIMITEDActive - Proposal to Strike off- SC410220 - Incorporated on 28 October 2011 
- RAPHAEL NEILL LTD- 09269823 - Incorporated on 17 October 2014 
- O’NEILL HOUSING LTDDisolved- SC687751 - Dissolved on 5 July 2022 
- MOGER AND NEILL LTDDisolved- 12813970 - Dissolved on 18 January 2022 
- O’NEILL LET LIMITED- 12453190 - Incorporated on 10 February 2020 
- O'NEILL'S ROOFING LTD- 15989938 - Incorporated on 1 October 2024 
- O' NEILL ROOFING LTD- SC847985 - Incorporated on 9 May 2025