The firm has been established for over 50 years and has many years of experience helping businesses and individuals to grow and flourish in Ireland.

We support our clients through their entire life-cycle — from initial establishment to growth and expansion in Ireland and overseas — ensuring they are not only compliant with laws and regulations, but also primed for growth and investment.


We have assisted dozens of Irish and international companies with their expansion plans. At home, we have helped US, Asian and European multinationals set up and run Irish operations.


Abroad, we have supported Irish companies in expanding into overseas territories or purchasing foreign companies. We also act as special advisors to US and European firms making acquisitions
in Ireland and Europe.

Duignan Carthy O’Neill is registered with the US based Public Company Accounting Oversight Board (PCAOB) which enables the firm to undertake the audit of USA Public Company Subsidiaries located in Ireland and the UK


Authorised by the Institute of Chartered Accountants in Ireland to carry on Audits and Business Activities.

Member of AGN International Ltd an association of independent accounting and financial advisory businesses.

© 2015 DUIGNAN CARTHY O'NEILL. Chartered Accountants, Registered Auditors, Dublin, Ireland. All Rights Reserved.