The 1998 U.S. Open Cup ran from June through October, 1998, open to all soccer teams in the United States. The first-year Major League Soccer club Chicago Fire won the Cup with a 2–1 overtime victory over the Columbus Crew at Soldier Field in Chicago, Illinois. In the early rounds of the tournament, only one MLS team lost to a minor-league side, when the A-League's Nashville Metros beat the Kansas City Wizards 3–1.

Open Cup Bracket

Home teams listed on top of bracket

First round

Eight D3 Pro, four PDL, and four USASA teams start.

Second round

Eight A-League enter.

Third round

Eight MLS enter.

Quarterfinals

Semifinals

Final

Top scorers