The 1998 King of the Ring was the sixth annual King of the Ring professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE) that featured the 12th King of the Ring tournament. It took place on June 28, 1998, at the Pittsburgh Civic Arena in Pittsburgh, Pennsylvania.

Nine matches were scheduled on the event's card. The main event was a First Blood match featuring Kane defeating Stone Cold Steve Austin for the WWF Championship. The other main match was a Hell in a Cell match featuring The Undertaker defeating Mankind. Featured matches on the undercard included the 1998 King of the Ring tournament final between Ken Shamrock and The Rock, which Shamrock won to win the tournament. Another prominent match was a tag team match for the WWF Tag Team Championship (which was only added to the card earlier that morning) between the New Age Outlaws defeating The Midnight Express, to retain the championship.

This event produced the best-known Hell in a Cell bout in history, pitting The Undertaker vs. Mankind; Michael Landsberg of TSN's Off the Record in 2002 called it "maybe the most famous match ever". Less than two minutes into the contest, The Undertaker threw Mankind from the top of the 16-foot (5 m) high cell through the Spanish announcers' table. The footage of that fall has since become one of the most used and viewed videos in professional wrestling history. A few minutes later in the match in another memorable moment, The Undertaker chokeslammed Mankind through the top of the cell, briefly knocking him legitimately unconscious.