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Miami, Florida

Service Experience
  • Advisory
  • Public sector

John O’Brien




Executive summary

John O’Brien is a Managing Director for Risk Advisory Services at Grant Thornton LLP. Grant Thornton LLP is the U.S. member firm of Grant Thornton International Ltd., one of the world’s leading organizations of independent audit, tax and advisory services. John is a member of the firm’s Public Sector Risk Advisory leadership team, with responsibility for leading the Information Assurance and Cybersecurity practices.

As a leader in the Public Sector Information Assurance practice, John leads attestation, assurance, and internal control engagements including SOC 1/2, ITGC testing in support of Financial Statement Audits, FISMA Performance Audits, and A-123 internal control reviews.

As a leader in the Public Sector Cybersecurity practice, John leads Grant Thornton’s readiness & compliance service offerings including FedRAMP and CMMC compliance. John has extensive experience with the implementation and assessment of compliance with NIST standards including SP 800-53, SP 800-37, and SP 800-171.

An accomplished Public Sector leader, John uses his background as both an IT auditor and consultant to assist his clients in determining the strongest and most efficient way to implement information security within their environment while meeting the mission of their business.

John is a Certified Information Systems Security Professional (CISSP), Certified Information Systems Auditor (CISA), Certified Information Systems Manager (CISM), and an AWS Certified Cloud Practitioner. He received bachelor’s degrees in Computer Information Systems and Business Administration from Elon University and is currently pursuing a master’s degree in Accounting from Florida Atlantic University.


Professional qualifications and memberships

  • Certified Information Systems Professional (CISSP) #518274
  • Certified Information Systems Auditor (CISA) #1299139
  • Certified Information Systems Manager (CISM) #1736595
  • AWS Certified Cloud Practicioner


  • B.S. Computer Information Systems, Elon University
  • B.S. Business Administration, Elon University
  • M.S. Accounting, Florida Atlantic University (candidate)

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