Aaron O’Connor, CPA

Partner, Elgin


With over 26 years of public accounting experience, Aaron joined PKF Mueller in 2020 as a Managing Director in our Audit and Assurance Group and is now a Partner. He has expertise in providing high-level assurance and advisory services with large international public accounting firms and brings deep GAAP and significant SEC reporting experience. Aaron’s experience includes significant capital raising transactions, both debt and equity, including private equity sponsors as well as assisting eight companies through the IPO process.

Aaron has significant experience in all aspects of accounting, auditing, risk management, and financial management. He also has provided guidance to C-suite executives and Board of Directors involving complex transactions and the related financial analysis and financial reporting requirements for those transactions. These transactions have included Mergers and Acquisitions, Divestitures, and Reorganizations.

Areas of Expertise

  • Audit Management
  • Capital & Debt Raising
  • Financial Reporting & Analysis
  • IPO & IPO Readiness
  • Risk Avoidance
  • M&A Due Diligence
  • Strategic Planning
  • Sarbanes Oxley (SOX)
  • Structuring
  • Growth Initiatives

He has extensive experience advising clients on financial analysis and reporting and offering real-world practical solutions that can be implemented in a cost-effective manner.

Aaron possesses exceptional expertise in leadership, coaching, and mentoring of staff. He has been a frequent speaker on industry matters and hot button topics.

Education & certifications

  • B.A., Economics and Accounting, Carthage College – All College Honors, Magna Cum Laude
  • Licensed Certified Public Accountant, Illinois

Professional & Civic Organizations

  • American Institute of Certified Public Accountants (AICPA)
  • Illinois CPA Society (ICPAS)
  • Financial Managers Society, Past President and Board member – Chicago Chapter


  • How Business Owners Can Prepare to Sell Their Business. PKF Mueller Insights and PKF Advisory
  • COVID-19: Balance Sheet – Caution Ahead. PKF Mueller Insights and PKF Advisory