John P. Nyhan

John P. Nyhan


“My business background helps me understand our clients’ needs and provides a frame of reference that’s consistent with their views.”

John P. Nyhan

John P. Nyhan represents a variety of clients in state and local property tax, valuation and planning matters. Prior to joining O’Keefe Lyons & Hynes in 2013, John was Chief of Staff at the Board of Review for Cook County, a quasi-judicial real estate tax tribunal, where property owners appeal valuations set by the Assessor. In addition to supervising day-to-day operations, John acted as the Board’s senior hearing officer, resolving complex commercial and industrial property valuation claims.

Prior to working at the Board of Review, John represented the Cook County Assessor’s Office, including as its Chief Legal Counsel. In that capacity, John served on the Assessor’s Executive Committee with oversight responsibility for several departments within the office. Before becoming an attorney, John held various marketing and management positions including opening a subsidiary in the United Kingdom for a U.S. manufacturer.

“In government, I worked with professionals who were committed to equitable and reasonable outcomes for property owners. My colleagues at O’Keefe, Lyons & Hynes exhibit the same dogged determination to achieve a fair, reasonable and just result for the clients we serve.”

Member of:

Chicago Bar Association

Illinois Property Assessment Institute: Certified Illinois Assessing Officer

International Association of Assessing Officers

International Association of Assessing Officers: Assessment Administration Specialist

bar admissions

Illinois Supreme Court, 1998

U.S. Court of Appeals for the Seventh Circuit, 1998

U.S. District Court for the Northern District of Illinois, 1998


DePaul University College of Law (Chicago), J.D., 1998

DePaul University, MBA/Finance, 1998

Santa Clara University (California), B.A., 1986

government service

Board of Review, Cook County, Chief Deputy Commissioner, 2011 – 2013

Cook County Assessor’s Office, 2003 – 2011

  • Chief Legal Counsel
  • Director, Legal Department
  • Director, Special Assessment Program
  • Staff Attorney