The 1998 United States Senate election in Iowa was held November 3, 1998. Incumbent
RepublicanUnited States SenatorChuck Grassley sought re-election to a fourth term in the
United States Senate, running against former
State Representative David Osterberg, who won the
Democratic nomination unopposed. Grassley had not faced a competitive election since
1980; this year proved no different, and Grassley defeated Osterberg in a landslide.