1998 St. Charles County Executive election

The 1998 St. Charles County Executive election took place on November 3, 1998. Incumbent Republican County Executive Joe Ortwerth ran for re-election to a second term. He was challenged in the Republican primary by former State Representative Ron Stivison, and he won renomination with 78 percent of the vote. In the Democratic primary, St. Charles Mayor Robert Moeller defeated former County Presiding Judge Lee Schwendemann with 60 percent of the vote, and advanced to the general election against Ortwerth. Moeller outspent Ortwerth and attracted local union endorsements, but Ortwerth won re-election in a landslide, receiving 60 percent of the vote to Moeller's 40 percent.