Mary K. O'Brien
Mary K. O'Brien (born June 4, 1965) is an American judge and politician. Early life and education. Born in Kankakee, Illinois, O'Brien grew up on a farm in Reddick, Illinois. She graduated from Reddick High School and went to Joliet Junior College. O'Brien received her bachelor's degree from Western Illinois University in 1986 and her J.D. degree from the University of Illinois College of Law in 1994. Illinois House of Representatives. In 1996, she defeated Republican incumbent Stephen Spangler to represent the 75th district. The 75th district, at the time, included all of Grundy County and  parts of LaSalle, Kankakee, and Will County, Illinois counties. From 1997 to 2003, O'Brien served in the Illinois House of Representatives and was a Democrat. The 2001 decennial reapportionment, added portions of Iroquois and Livingston counties. O'Brien resigned from the Illinois House of Representatives on December 17, 2003. Judicial service. O'Brien was appointed a judge of the Third District of the Illinois Appellate Court to fill the vacancy created by the retirement of Thomas J. Homer. She was sworn in on December 26, 2003. The Third District comprises Bureau, Fulton, Grundy, Hancock, Henderson, Henry, Iroquois, Kankakee, Knox, LaSalle, Marshall, McDonough , Mercer, Peoria, Putnam, Rock Island, Stark, Tazewell, Warren, Whiteside, and Will. Judge O’Brien was elected to the court in 2004 and retained in 2014. O'Brien is running in the Democratic primary for the 2022 election to the third district seat on the Illinois Supreme Court. She has been endorsed by United States Senator Dick Durbin.