The eighteenth season of the American animated television series The Simpsons aired from September 10, 2006 to May 20, 2007. The season contained seven hold-over episodes from season 17’s HABF production line. Al Jean served as the showrunner, a position he has held since the thirteenth season, while the season was produced by Gracie Films and 20th Century Fox Television.
 The season finale, "You Kent Always Say What You Want", was the series' 400th episode. Additionally, the Simpsons franchise celebrated its 20th anniversary, as it has been on the air since April 1987, beginning with shorts on The Tracey Ullman Show.
 Season 18 included guest appearances by Metallica, Tom Wolfe, Gore Vidal, Michael Chabon, Ludacris, Jonathan Franzen, Fran Drescher, The White Stripes, Kiefer Sutherland, Mary Lynn Rajskub, Richard Lewis, Dr. Phil, Elvis Stojko, Natalie Portman, Jon Lovitz, Betty White, Eric Idle, Sir Mix-a-Lot, Stephen Sondheim, Ronaldo, Meg Ryan, Andy Dick, Peter Bogdanovich, James Patterson and others.
 Robert Canning of IGN gave the season a 6.6 saying it was "Passable" and that "Now in its eighteenth season (go ahead, say that out loud: 'eighteen seasons'), The Simpsons continues to supply America with a decent half-hour of comedy every Sunday night. However, most long-time fans of the show agree that the last several years have seen the program in constant decline. Looking back at this particular season, there's little evidence to prove them wrong. Though we were treated with at least a few hilarious gems this year, the mediocre (to the downright terrible) heavily outweighed the great."
 At the 35th Annie Awards, Alf Clausen and Michael Price won the award for "Best Music in an Animated Television Production" for "Yokel Chords" while Ian Maxtone-Graham and Billy Kimball won "Best Writing in an Animated Television Production" for "24 Minutes" Jeff Westbrook won a WGA Award for "Kill Gil: Vols. 1 & 2" while Matt Selman was nominated for "The Haw-Hawed Couple" and John Frink received a nomination for "Stop, or My Dog Will Shoot".
 The series also received a British Comedy Award nomination for "Best International Comedy" a Primetime Emmy Award nomination for Outstanding Animated Program for "The Haw-Hawed Couple" and an Environmental Media Award nomination for "Best Television Episodic Comedy" for "The Wife Aquatic".
 The show ranked 60th in the seasonal ratings with an average of 8.6 million watching it and a Nielsen rating of 4.1/10.
 Lisa becomes friends with Fat Tony's son Michael, who would rather cook than run a crime ring, but when the Simpsons are invited over for dinner and Fat Tony is shot, Homer ends up being the town's newest kingpin.
 Bart gets a drum kit to work out his aggression after being a nuisance at the funeral of Homer's Vegas wife and becomes top pick for a local jazz band -- a position that the saxophone-playing Lisa has been going after for years. Meanwhile, Lisa begins adopting abandoned animals.
 Season 18's annual trio of Halloween stories."Married to the Blob" - Homer eats a mysterious green substance from a meteorite landing that turns him into a giant blob with an insatiable, cannibalistic appetite."You Gotta Know When to Golem" - Bart discovers a golem backstage at Krusty's show and uses it to do his bidding."The Day the Earth Looked Stupid" - After being fooled by H.G. Wells' War of the Worlds, the citizens of Springfield in 1938 ignore a real alien invasion set up by Kang and Kodos.
 Homer finds himself in an army training camp after trying to get his children out of an agreement to join by age 18.
 Lisa discovers that Moe's written rantings are perfect fodder for poetry, but when Moe is invited to a writer's convention, he takes credit for her work.
 After Gil Gunderson gives Lisa a Malibu Stacy doll reserved for Mr. Costington's daughter, he gets fired as a mall Santa and moves in with the Simpsons. Meanwhile, Homer picks a fight with Ice Capades character The Grumple.
 When Patty and Selma save "Outdoor Movie Night" from going bust by playing an old home movie of their time at Barnacle Bay, Homer decides to surprise Marge by taking her and the kids there -- only to find her childhood vacation spot an abandoned wreck.
 When Cletus ineptly tosses his pipe, Springfield is in danger when the town is about to be hit by a ferocious fire. Bart unwittingly saves the day and is rewarded with a driver's license. However, when he drives to North Haverbrook after he loses his temper from Homer with a phone, he is then engaged with a girl named Darcy who ropes Bart into marriage after declaring that she is pregnant. Meanwhile, Lisa lies about her family heritage in an essay and gets chosen to give a keynote speech at a convention.
 Declan Desmond returns as he shows a documentary about Springfield's current adult population as children, discussing their future aspirations and meeting up with Homer to see if he followed his dreams.
 Lisa becomes a tutor for Cletus Spuckler's children after Principal Skinner bars them from enrolling in Springfield Elementary. Meanwhile, Bart ends up in therapy after scaring his peers with stories of a school chef notorious for cooking children.
 When Grampa gets kicked out of the retirement castle thanks to Homer declaring bankruptcy (and discovering that bankruptcy laws have changed), Grampa falls in love with Marge's sister Selma, prompting sworn enemies Homer and Patty to team up to break them up. Meanwhile, Bart and Lisa con a delivery man into giving them cardboard boxes for a fort, but the delivery men fight back.
 After the family photo album is destroyed in a fire involving a Krusty doll and a bottle of cologne, Marge restages all of the family's photographs, and when a celebrity dating scandal is captured in the background of one of their photos, the Simpsons strike tabloid gold. Tasting success and seeing money to be made, Homer takes to the streets as one of the paparazzi, capturing Springfield's celebrities at their worst.
 Marge discovers the wonders of the Internet and becomes hooked on an online roleplaying game, where Bart is the game master. Meanwhile, Lisa resorts to cheating to score points with Homer (who is now a referee) during soccer matches.
 When Homer gets lost in a cornfield maze, Santa's Little Helper rescues him and becomes a local hero, which prompts the Simpson family to enroll him in Police Dog Academy, where he dons a new and more stern personality. However, he becomes jaded when he catches Snake Jailbird, who is released on a technicality, and bites Bart, causing the family to give him away. Meanwhile, Bart, missing Santa's Little Helper, gets a strangling snake as a new pet.
 When finding out Jimbo, Dolph, and Kearney plan on sabotaging Springfield Elementary School's annual bake sale by releasing the "ultimate stink bomb" (a rotten yogurt cup from Springfield's Nuclear Power Plant), Bart and Lisa enlist the help of Jack Bauer and Chloe O'Brian. Meanwhile, Marge attempts to make the perfect cake for the school bake sale.
 Due to Ned Flanders' meddling, Kent Brockman gets in trouble for blurting a horrible curse word during a soft-news interview about Homer winning Phineas Q. Butterfat's 1,000,000th ice cream cone, and gets fired for allegedly being a cocaine addict. While living with the Simpsons, Brockman teams up with Lisa to create a YouTube video revealing why a politically conservative media empire like Fox would create raunchy television shows.
 Guest stars: Ludacris and Maurice LaMarche.
 Series showrunner Al Jean reported in April 2015 that The Simpsons would no longer see home media releases after the seventeenth season, claiming an inability for DVD sales to keep up with the rise in streaming and downloads, as well as a boom in FXX reruns, and Fox's on-demand video service, FXNOW. Jean reassured that bonus features commonly featured on the DVDs, such as commentaries for each episode, would still be available, now packaged with the digital format.
 In 2016, audio commentary for the 18th season was made available exclusively through FXNOW.
 On Saturday, July 22, 2017, it was announced during the San Diego Comic-Con 2017 panel that, due to fan demand, the eighteenth season DVD would be released after all on Tuesday, December 5, 2017, in the United States and Canada by 20th Century Fox Home Entertainment, ten years after it had completed broadcast on television.