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About the Auditor

Denver’s Auditor, Timothy M. O’Brien, CPA, has more than 40 years of auditing and accounting experience. Auditor O'Brien strives to bring greater clarity, transparency, and accountability to Denver's City government for its residents. Elected as the Denver Auditor in 2015, Timothy O'Brien is distinguished from his predecessors by being an actual professional auditor.  He is a licensed Certified Professional Accountant and holds the designations of Chartered Financial Analyst and Chartered Global Management Accountant.

In his 11 years in Colorado's top auditing job, the Colorado State Auditor, Auditor O’Brien:

-Pushed for the Great Colorado Payback program that returned almost $400 million to the rightful owners,

- Produced over 750 financial and performance audits,

- Identified savings of over $200 million,

- Managed budget increases to less than 1.5% per year, and

- Was twice recognized by the non-partisan National Conference of State Legislatures for his legislative program.

As a Board member, an Audit Committee expert, and as an auditor, Auditor O’Brien: 

  •     Participated in hundreds of audits.
  •     Facilitated the merger between two publicly held corporations.
  •     Advised public pension plans.

Auditor O’Brien has led both private and public organizations, and provided expert financial advice to those and others. He was honored with the 2016 Jonathan Holtzinger Award of Excellence by the Colorado Chartered Financial Analyst Society for demonstrating the highest standards as a financial and investment professional. Auditor O'Brien also received the 2017 Outstanding CPA in Government Impact Award from the American Institute of CPAs.

Auditor O'Brien's experience includes:   

  • Chairman, Board of Trustees, Public Employee Retirement Association of Colorado (PERA)
  • Chairman of the Board, family of 29 mutual funds
  • President and CEO, American Humane Association
  • Chairman of the Board and Chair of the Audit Committee, Colorado Housing and Finance Authority (CHFA)
  • Board Member and Chairman of the Audit Committee of a telecommunications company
  • Board Member and Treasurer, Lions Club of Denver
  • President and Board Member, Colorado Society of CPAs
  • Governing Council Member, American Institute of CPAs
  • Investment Advisory Council Member, Alaska State Pension Investment Board

Auditor O’Brien’s professional associations include:

  • Colorado Society of CPAs (licensed since 1974)
  • American Institute of CPAs
  • Chartered Financial Analyst Institute
  • Colorado Society of Chartered Financial Analysts (licensed since 1999)
  • National Association of State Auditors (life member)


  • B.S.B.A. Accounting major, Loyola University- Chicago
  • M.B.A. University of Colorado

Personal life: Tim O'Brien lives in Southeast Denver with his wife Mary Frances Kelley. They have three wonderful daughters and an adorable grandson.  Auditor O'Brien can be reached by calling (720) 913-5002 or emailing


Auditor O'Brien in the News

Comcast Newsmakers: Taxpayers' Money


COCPA: Catching Up with the Auditor >> Click Below

COCPA Interview: Catching Up with Denver Auditor Tim O'Brien


Auditing Functions in the Region

Denver’s Auditor is publicly elected and answers to the voters. The role of the Auditor – and internal auditing functions in general – is to help minimize risks, improve internal controls, maximize efficiencies, and strengthen accountability. Not all municipalities or even states have elected Auditors, and some do not have internal auditing functions at all.

  • Colorado Springs’ Auditor is appointed by its City Council.
  • Boulder has internal auditing within its Finance Department.
  • Jefferson County outsources audits from time to time, although it does have an Audit Committee that meets quarterly.
  • Colorado has an appointed Auditor, who is nominated by the Legislative Audit Committee and confirmed by the state legislature.
  • Denver has all four: an elected Auditor, internal auditing staff, external auditors, and an appointed Audit Committee.