1998 (MCMXCVIII) was a common year starting on Thursday of the Gregorian calendar. A majority of season 1 was produced in this year.
| Date | Event(s) | |
|---|---|---|
| Unknown date | The Best of Nicktoons 1998 was released. 26 episodes of season 1 were produced. | |
| April 1 | United Plankton Pictures, Inc. was founded. | |
| June 24 | The date when "Sandy's Rocket" was renamed to the current title. It was called "Space Show" before this day. | |
| September 3 | "Tea at the Treedome" was produced. | |
| September 28 | "Jellyfish Jam" was storyboarded. | |
| October 12 | "Sandy's Rocket" was produced. | |
| October 26 | "I Was a Teenage Gary" was storyboarded. | |
| December 11 | "Home Sweet Pineapple" was storyboarded. | |