Mayor Brennan was elected Mayor of University Heights in 2017. Mayor Brennan is active on various boards and commissions, including: Northeast Ohio Area Coordinating Agency (NOACA); Northeast Ohio Regional Sewer District (NEORSD) Suburban Council of Governments; Northeast Ohio First Suburbs Consortium; Suburban Water Council of Governments; Heights Hillcrest Communications Center Board of Trustees.

Mayor Brennan received his Juris Doctor from Cleveland-Marshall College of Law (1996), and a Bachelor of Arts degree in Political Science from Bowling Green State University (1993). Prior to serving in public office, Mayor Brennan was a litigator in private practice.