Mark O’Riordan

Mark joined Meridian in 1998 and was appointed Chairman and Chief Executive in October 2004. Prior to this he was Operations Manager at BBL Finance Ireland, an international merchant bank.

Since 1998, Mark has held a variety of executive positions within Meridian, namely Operations Director, Managing Director North America, Client Services Director EMEA and Director of Business Services, Mark also had responsibility for the Groups Treasury requirements during this time. Mark took over the position of Chairman and Chief Executive in 2004.

Mark is passionate about the business Meridian is involved in and personifies Meridian's commitment to delivering the highest quality services to its clients around the world. Mark is a qualified Chartered Accountant (FCA) and holds an MBA from The Open University.

Derek O'Brien

Derek was appointed Chief Operating Officer Tax Technology in 2018 with responsibility for leading the Tax Technology business and continues to have responsibility for the Group marketing activities in Meridian. Derek joined Meridian in March 2001 and has held several management positions during his time with Meridian and has been involved in New Product Development, Strategic Alliances and Go To Market.

In the more than 20 years with Meridian Derek has cultivated a strong and extremely productive relationships with a lot of our most strategic clients and partners. He began his career with some of Ireland’s largest retailers, in several operations management positions. Derek is a Graduate member of the Marketing Institute of Ireland (MMII Grad).

Michelle Lang

Michelle Lang is a Director of Consulting with Meridian Global Services and is based in our Dublin office. Michelle provides support and VAT advice on issues relating to Meridian clients operating in multiple EU jurisdictions across a broad range of industries, including the pharma and manufacturing sectors.

Michelle has over 15 years’ experience in VAT having worked with Deloitte prior to joining Meridian in 2013. Michelle holds a degree in Finance and is a qualified member of the Institute of Taxation in Ireland.