Duignan Carthy O’Neill was formed in 1998 arising from a merger of Duignan & Co., and Carthy O’Neill & Co., two Dublin-based chartered accounting firms established for over 40 years. The practice has grown over the years to include a comprehensive range of accounting, tax and financial advisory services. This growth has been based on building long-term relationships with entrepreneurial, growth-oriented Irish and international businesses across a broad range of industries.