The Cook County, Illinois, general election was held on November 3, 1998.
Primaries were held on March 17, 1998.
Elections were held for Assessor, Clerk, Sheriff, Treasurer, President of the Cook County Board of Commissioners, all 17 seats of the Cook County Board of Commissioners, all 3 seats of the Cook County Board of Review, 4 seats on the Water Reclamation District Board, and judgeships on the Circuit Court of Cook County.
1998 was a midterm election year in the United States. The primaries and general elections for Cook County races coincided with those for federal (Senate and House) and those for state elections.
Voter turnout in Cook County during the primaries was 28.68%.
On its own, suburban Cook County saw 23.95% turnout.
The general election saw 54.61% turnout, with 1,433,423 ballots cast. Chicago saw 752,506 ballots cast while suburban Cook County saw 53.95% turnout (with 680,917 ballots cast).
In the 1998 Cook County Assessor election, incumbent assessor James Houlihan, a Democrat, was elected to his first full-term. Houlihan had been appointed to the office in 1997, after Thomas Hynes (who had served as Cook County assessor since 1978) opted to resign from the office.
In the 1998 Cook County Clerk election, incumbent second-term clerk David Orr, a Democrat, was reelected.
In the 1998 Cook County Sheriff election, incumbent second-term sheriff Michael F. Sheahan, a Democrat, was reelected.
Former Superintendent of the Chicago Police Department LeRoy Martin won the Republican primary.
In the 1998 Cook County Treasurer election, incumbent sixth-term treasurer Edward J. Rosewell, a Democrat, did not seek reelection after having been indicted over a ghost jobs scheme (for which he would ultimately plead guilty). Cook County Commissioner Maria Pappas was elected to succeed him.
In the 1998 President of the Cook County Board of Commissioners election, incumbent first-term president John Stroger, a Democrat, was reelected.
Incumbent John H. Stroger, Jr. defeated Cook County commissioner Calvin R. Sutker.
Clerk of the Circuit Court of Cook County Aurelia Pucinski left the Democratic Party and joined the Republican party in December 1997 to run as its nominee for President of the Cook County Board of Commissioners.
The 1998 Cook County Board of Commissioners election saw all seventeen seats of the Cook County Board of Commissioners up for election to four-year terms.
In the 1998 Cook County Board of Review election, all three seats were up for election. This was the first election for what would be a newly reconstituted body. In 1996, the Illinois Legislature successfully passed Public Act 89-671, which made it so that, in 1998, the Cook County Board of Appeals would be renamed Cook County Board of Review and be reconstituted as a three-member body.
All elections held in 1998 were for four-year terms.
Republican Maureen Murphy defeated Democrat David McAfee.
Joseph Berrios a ten incumbent on the predecessor organization, the Cook County Board of (Tax) Appeals, was elected, running unopposed in both the Democratic primary and general election.
No candidates ran in the Republican primary.
Robert Shaw, a Democrat, was elected.
No candidates ran in the Republican primary.
In the 1998 Metropolitan Water Reclamation District of Greater Chicago election, four of the nine seats on the Metropolitan Water Reclamation District of Greater Chicago board were up for election. Three were regularly scheduled elections, and one was a special election due to a vacancy.
Democrats won all four seats up for election.
Democratic incumbents Gloria Alitto Majewski and Patricia Young were reelected in the at-large election.
Three six-year term seats were up for an at-large election. Since three six-year seats were up for election, voters could vote for up to three candidates, and the top-three finishers would win.
A special election was held to fill a seat left vacant.
Partisan elections were held for judgeships on the Circuit Court of Cook County, due to vacancies. Other judgeships had retention elections.
Partisan elections were also held for subcircuit courts judgeships due to vacancies. Other judgeships had retention elections.
One ballot question was included on ballots county-wide during the March primary election.
An advisory referendum was included on the March primary ballots on the Managed Care Act.
Coinciding with the primaries, elections were held to elect both the Democratic and Republican committeemen for the suburban townships.