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Greg Wallig




Executive summary


Greg is the Managing Principal of Grant Thornton’s MetroDC-Arlington office, the firm’s largest domestic office, and the fourth largest public accounting firm in the MetroDC region. He is one of our firm’s leading faces to the DC market, representing Grant Thornton’s 1200 local employees in the country’s fifth largest economy.

Named to the Virginia 500 Power List, Greg is a people-first leader, who believes deeply that diverse perspectives produce better outcomes. He has long championed Grant Thornton’s Diversity, Equity and Inclusion efforts, and in 2021 was recognized as a national leader for his contributions as a diversity advocate in the DC region.

Unique to Greg is his breadth of experience: he has worked across multiple industry segments, from technology, to public sector, financial services and healthcare, and his personal and professional experience spans five of the seven continents, with particular expertise working between the US, Europe and India. His professional acumen spans audit, investigations, analytics, business process improvement and technology innovation. This experience provides Greg a wide lens he uses to address his clients’ biggest challenges in a comprehensive way.

As a compliment to his leadership role at Grant Thornton, Greg also serves on the boards of the Greater Washington Board of Trade, Virginia Society of CPAs, the Rosslyn Business Improvement District, the Global Fund for Children, and the Masters of Science in Business Analytics at William & Mary.



Professional qualifications and memberships

  • Certified Information Systems Auditor (CISA) * Certified in the Governance of Enterprise Information Technology (CGEIT)
  • Congressional Roll Call
  • Public Risk Magazine
  • Irish Times
  • Journal of Cost Management


Presentations and publications

  • Program Leader and Creator, The Potomac Forum, “Continuous Monitoring – Continuous Diagnostics,” 2014.
  • Moderator, Association of Government Accountants, Professional Development Conference, “Transformational Compliance,” 2014.
  • Program Leader and Creator, The Potomac Forum, “Advanced Internal Controls:  Beyond OMB A-123 Requirements Including Its Impact on Performance Management and Budgeting,” 2013.
  • Presenter, Association of Government Accountants, Professional Development Conference, “Cloudy with a Chance of Risk,” 2013.
  • Author, “Expanding the Enterprise in Enterprise Risk Management,” Association of Government Accountants Journal, Spring 2012.



  • BA, International Relations, College of William and Mary

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