1998 Isle of Man TT

The 1998 Isle of Man TT was the 92nd edition of the event. Due to the high amount of rainy days, the Sidecar Race A was cancelled. It was only the second time a race was cancelled in the history of the event. The TT Formula One was also postponed by a day.

Ian Simpson was the only rider to win muptiple races, taking the opening and closing races, the Formula One TT and the Senior TT. It was Simpson's last participation at the TT as leg injuries prevented him from competing in 1999, before forcing him into early retirement in early 2001.

Three competitors died during the event, Mike Casey, Ian Hardisty and John Henderson. A fourth rider, 66-year old Jack Trustham, died of a heart attack during a parade lap commemorating Honda's achievements on the island.