Bill Brady was the Republican Minority Leader of the Illinois Senate from July 1, 2017, to December 31, 2020.

On November 4, 2020, Brady announced he would step down as Senate party leader and would "[hint] at another run for statewide office.

[7] Alongside the inauguration of the 102nd General Assembly, McConchie was formally confirmed as Republican Minority Leader on January 13, 2021.

Javier Cervantes, a business manager for Service Employees International Union, was the Democratic nominee.

Aquino faced Wilmer Maldonado and Wilson Vazquez, a Teamster,[16] for the Democratic nomination.

Fellow state Representative Kelly Cassidy and CEO of Blue Sky Strategies Mike Simmons were considered the front runners for appointment.

Martwick faced Erin Jones, a former CPD police officer,[21] for the Democratic nomination.

Villanueva faced Javier Yanez, former chief of staff for Alderman Byron Sigcho-Lopez,[24] for the Democratic nomination.

The district had been represented by Democratic Deputy Majority Leader Emil Jones III since January 14, 2009.

The district had been represented by Democratic Assistant Majority Leader Jacqueline Y. Collins since January 8, 2003.

[25] Willie Preston, a small business owner,[26] and La'Mont Raymond Williams, an attorney,[27] ran for the Democratic nomination.

After being elected Clerk of the Circuit Court of Cook County, Martinez resigned her seat in November 2020.

Cullerton resigned his seat on February 23, 2022, after announcing his intent to plead guilty to federal embezzlement charges.

Joshua Alvarado, a video production artist,[39] and Bill Robertson, a former school superintendent,[40] ran for the Republican nomination.

The district had been represented by Democratic Deputy Majority Leader Laura Murphy since her appointment on October 5, 2015.

Terry Link resigned his seat on September 12, 2020, because of "roughly a month after he was charged with a federal count of income tax evasion.

"[42] On September 16, 2020, Link "pleaded guilty to a federal count of filing a false tax return.

[47] The district had been represented by Republican Assistant Minority Leader Don DeWitte since his appointment in September 2018.

[49] Glen Evans, a minister,[50] and Rock Island Mayor Mike Thoms ran for the Republican nomination.

Stoller defeated Brett Nicklaus, a certified financial planner, for the Republican nomination.

Philip Nagel, a former United States Air Force crew chief,[54] and Krystyna Vela, a real estate agent,[55] ran for the Republican nomination.

[59] Dianne Harris, a small business owner,[60] and Michelle Lee, a Joliet Junior College board of trustees member,[61] ran for the Republican nomination.

[67] Springfield City Council and Sangamon County Board member Doris Turner was appointed on February 6, 2021.

Stacey Keagle, a nurse,[69] James Lawson, an electrician,[70] and Felicity Joy Solomon, a life coach,[71] all ran for the Republican nomination.

Keagle would initially win the nomination but later dropped out of the race on August 26, 2022, due to health issues.

State Senator Jil Tracy from the 47th legislative district was redistricted to the 50th and faced no other ballot-listed candidates in the general election.

[74][75] Champaign Township Assessor Paul Faraci was appointed to serve out Bennett's term and was sworn into office on January 11, 2023.

On February 22, 2021, Bailey announced his intention to run in the 2022 Illinois gubernatorial election and would be nominated as the Republican nominee.

[77] State Senator Jason Plummer from the 54th legislative district was redistricted and faced no other ballot-listed candidates in the general election.

After being nominated to serve as United States Attorney for the Southern District of Illinois, Crowe resigned from the Senate on June 15, 2022.