Auditor Timothy M. O'Brien

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 in 2015 and reelected in 2019, 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.

Auditor at the officeTimothy O'Brien speaking at a community event


Auditor's Experience

  • Appointment to the U.S. Comptroller General’s Advisory Council on Government Auditing Standard.
  • 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 was honored to receive the following recognitions for his professionalism and contributions to government auditing and leadership in government:

  • 2022 David M. Walker Excellence in Government Accountability Award by the National Intergovernmental Audit Forum for his demonstrated leadership to improve government performance and accountability, implemented innovative techniques to create a positive future for government and the audit profession, and adherence to the core values of collaboration, professionalism, and integrity.

  • Five Knighton Awards by the Association of Local Government Auditors for the best performance audit reports of the year among local governments in the U.S. and Canada.
  1. Knighton Distinguished Award in 2022 for the audit of passenger parking shuttles at Denver International Airport(PDF, 3MB).
  2. Knighton Exemplary Award in 2021 for the audit of Denver’s Neighborhood Sidewalk Repair Program(PDF, 8MB)
  3. Knighton Award for the 2019 audit of the Denver Preschool Program(PDF, 14MB).
  4. Knighton Distinguished Award for the first Affordable Housing audit(PDF, 7MB) from 2018.
  5. Knighton Exemplary Award for the 2015 Rocky Mountain Human Services audit(PDF, 5MB)
  • 2018 ADA Access Award from the Colorado Cross-Disability Coalition for his work on behalf of people with disabilities.

  • 2017 Outstanding CPA in Government Impact Award from the American Institute of CPAs.

  • 2016 Jonathan Holtzinger Award of Excellence by the Colorado Chartered Financial Analyst Society for demonstrating the highest standards as a financial and investment professional.


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

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.


Professional Associations

  • 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)

Education & Personal Life

Auditor O'Brien holds a B.S.B.A. Accounting major from Loyola University- Chicago, and a M.B.A. from University of Colorado.

He lives in Southeast Denver with his wife Mary Frances Kelley. They love spending time with their three wonderful daughters and their adorable grandchildren. Auditor O’Brien can be reached by calling (720) 913-5002 or emailing

Timothy O'Brien Official Headshot
Denver's Auditor

Denver Auditor's Office
201 W. Colfax Ave. #705 Denver, CO 80202
Call: 720-913-5000
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