1998

All events that happened in 1998.

January

 * 4th: "All Singing, All Dancing" aired for the first time.
 * 11th: "Bart Carny" aired for the first time.

February

 * 3rd: The Best of The Simpsons: Volume 4 is released on VHS.
 * 8th: "The Joy of Sect" aired for the first time.
 * 15th: "Das Bus" aired for the first time.
 * 22nd: "The Last Temptation of Krust" aired for the first time.

March

 * 1st: "Dumbbell Indemnity" aired for the first time.
 * 8th: "Lisa the Simpson" aired for the first time.
 * 22nd: "This Little Wiggy" aired for the first time.
 * 29th: "Simpson Tide" aired for the first time.

April

 * 8th: "The Trouble with Trillions" aired for the first time.
 * 14th: Sex, Lies & the Simpsons was released on VHS for the United Kingdom.
 * 17th: Linda McCartney, musician and guest star, died.
 * 19th: "Girly Edition" aired for the first time.
 * 26th: "Trash of the Titans" aired for the first time.

May

 * 3rd: "King of the Hill" aired for the first time.
 * 10th: "Lost Our Lisa" aired for the first time.
 * 17th: "Natural Born Kissers" aired for the first time. Season 9 ended.
 * 18th: The Simpsons: Against the World was released on VHS for the United Kingdom.
 * 28th: Phil Hartman, voice of Lionel Hutz and Troy McClure, died.
 * 28th: Bill Williams, the original designer for The Simpsons: Bart's Nightmare, died.

August

 * 21st: Season 10 started. "Lard of the Dance" aired for the first time.
 * 31st: The Simpsons: Heaven and Hell was released on VHS for the United Kingdom.

September

 * 20th: "The Wizard of Evergreen Terrace" aired for the first time.
 * 27th: "Bart the Mother" aired for the first time.

October

 * 25th: "Treehouse of Horror IX" aired for the first time.

November

 * 8th: "When You Dish Upon a Star" aired for the first time.
 * 9th: The Simpsons: The Last Temptation of Homer was released on VHS for the United Kingdom.
 * 15th: "D'oh-in' in the Wind" aired for the first time.
 * 22nd: "Lisa Gets an "A"" aired for the first time.

December

 * 6th: "Homer Simpson in: "Kidney Trouble"" aired for the first time.
 * 20th: "Mayored to the Mob" aired for the first time.