top of page
Obrien Homepage BGV2.jpg

Mary Kay O'Brien



Why Illinois Supreme Court

Mary Kay O’Brien is an experienced and highly qualified judge with deep roots in the community and a long history of public service.

 Justice O’Brien has served on the 3rd District Appellate Court for over 19 years. She has heard more than 4,500 cases and served on numerous committees.

Defeating an incumbent, O’Brien secured the Democratic majority in the House of Representatives.

O’Brien was raised on the family farm in Reddick, Illinois where she learned the importance of hard work, integrity, and public service from her parents. Justice O’Brien earned her law degree, worked for former Attorney Generals Neil Hartigan and Roland Burris, worked in the Grundy County State’s Attorney’s Office, and private practice covering family law, criminal law, real estate, banking, and municipal law.


Elected Officials

Labor Organizations

  • U.S. Senator Tammy Duckworth 

  • U.S. Senator Richard J. Durbin 

  • U.S. Representative Sean Casten 

  • U.S. Representative Bill Foster 

  • U.S. Representative Mike Quigley 

  • Illinois State Comptroller Susana Mendoza 

  • Illinois Secretary of State Jesse White

  • DuPage County Clerk of the Circuit Court Candice Adams

  • Kankakee County State’s Attorney Jim Rowe 

  • Kankakee County Recorder Lori Gadbois 

  • Kankakee County Board Member Steve Hunter

  • Kankakee County Board Member Rosemary Foster

  • Kankakee County, Pembroke Township Supervisor Samuel Payton

  • Kankakee County, Hopkins Park Mayor Mark Hodge

  • Will County Executive Jennifer Bertino-Tarrant 

  • Will County Auditor Duffy Blackburn 

  • Will County Treasurer Tim Brophy 

  • Will County Circuit Court Clerk Andrea Lynn Chasteen 

  • Will County Clerk Laura Staley Ferry

  • Will County Recorder of Deeds Karen Stukel 

  • Will County Coroner Laurie Summers 

  • Will County Regional Supt. of Schools Shawn Walsh 

  • State Sen. Meg Loughran Cappel 

  • State Sen. John Connor (retired)

  • State Sen. Laura Ellman 

  • State Sen. Sara Feigenholtz 

  • State Sen. Suzy Glowiak Hilton 

  • State Sen. Linda Holmes 

  • State Sen. Patrick Joyce

  • State Rep. Dagmara “Dee” Avelar 

  • State Rep. Deb Conroy 

  • State Rep. John D’Amico 

  • State Rep. Anthony DeLuca 

  • State Rep. Jay Hoffman 

  • State Rep. Terra Costa Howard 

  • State Rep. Stephanie Kifowit 

  • State Rep. Natalie Manley 

  • State Rep. Michelle Mussman 

  • State Rep. Janet Yang Rohr 

  • State Rep. Anne Stava-Murray 

  • State Rep. Larry Walsh, Jr. 

  • State Rep. Ann Williams 

  • State Rep. Kathleen Willis 

  • State Rep. Lance Yednock 

  • State Rep. Michael Zalewski ​​

  • AFSCME Council 31

  • Associated Fire Fighters of Illinois

  • Chicago Fire Fighters Union Local 2

  • DuPage County Building and Construction Trades Council

  • Illinois AFL-CIO 

  • Illinois Federation of Teachers 

  • Illinois Education Association

  • Illinois State Association of Letter Carriers, National Association of Letter Carriers, Branch 825 

  • International Association of Sheet Metal Air Rail and Transportation Workers (SMART), Local 265

  • Illinois State Council of Sheet Metal Workers

  • International Union of Operating Engineers Local 399 

  • Joliet Firefighters Local 44

  • Kankakee & Iroquois County Building Trades Council

  • Mid-America Carpenters Regional Council 

  • North Central Illinois Labor Council

  • Operators Local 150

  • Painters District Council 14 

  • Painters District Council 30

  • Plumbers Local 130 UA 

  • Will & Grundy County Building Trades Council

  • UFCW Local 881

  • Former United States Attorney for the Northern District of Illinois Dan K. Webb

  • Appellate Court Justice Peg McDonnell Breslin (retired)

  • Appellate Court Justice Tom Homer (retired)

  • Coalition of Frontline Police Officers

    • ​Illinois Police Benevolent & Protective Association (“PBPA”)

    • Metropolitan Alliance of Police (“MAP”), Illinois Council of Police and Sheriffs (“ICOPS”)

    • Association of Professional Police Officers (“APPO)

  • Planned Parenthood Illinois Action (PPIA)

  • Indo-American Democratic Organization (IADO)

  • Personal PAC

  • Equality Illinois

  • Illinois NOW


bottom of page
Loading dynamic content...