The anime adaptation of The Melancholy of Haruhi Suzumiya (涼宮ハルヒの憂鬱, Suzumiya Haruhi no Yūutsu), produced by the Japanese animation studio Kyoto Animation and directed by Tatsuya Ishihara, contained 14 episodes which aired in Japan between April 2 and July 2, 2006. It was originally aired in a nonlinear order, with the prologue and first seven chapters of the first novel intermixed with chapters from some of the later novels. The "next episode" previews feature two different episode numberings: one number from Haruhi, who numbers the episodes in chronological order, and one number from Kyon, who numbered them in broadcast order. The DVD releases start with "Episode 00" and are then shown in chronological order.
The anime was licensed and distributed by Bandai Entertainment over four DVDs released between May and November 2007. A complete box set was released on July 29, 2008. It was broadcast in Italy on Rai 4 between October 24, 2010 and February 6, 2011. Each of the North American releases offered a limited edition collector's set featuring the English dub DVD in chronological order, a subbed-only disc containing the episodes in broadcast order, and an official CD release of the opening, ending, and insert songs appearing in the show.
The second season of the anime series was announced in a full-page advertisement of Asahi Shimbun on July 7, 2007 in Japan. Promotional videos included a live action sequence, inspired by the "Bamboo Leaf Rhapsody" chapter from the third novel The Boredom of Haruhi Suzumiya, depicting Haruhi and Kyon breaking into a school shown by footage taken from surveillance cameras. On December 18, 2007, the anime's official website, haruhi.tv, was replaced by a fake 404 error with five form-input fields, a reference to the pivotal date in The Disappearance of Haruhi Suzumiya, the fourth volume in the light novel series.
A re-broadcast of the first series began in April 2009. Following a comment by Teletama, one of the broadcasting stations, that the 2009 broadcast would be 28 episodes long, there was speculation that the re-broadcast would be followed by the second season, though this was not confirmed by Kadokawa at the time. The first new episode, "Bamboo Leaf Rhapsody" (笹の葉ラプソディ, Sasa no Ha Rapusodi), was aired on May 21, 2009, as the eighth episode of the re-broadcast. Unlike the original run the re-broadcast was shown in chronological order, with new episodes intermixed with the old ones. Episodes were later shown on Kadokawa's YouTube channel after the broadcast and started showing English-subtitled episodes. Bandai Entertainment licensed the re-broadcast in 2010 and released a complete collection in North America on September 14, 2010. Manga Entertainment released the season in a 4-disc DVD box set, including the Haruhi-chan mini-episodes, in the UK on July 4, 2011. Following the 2012 closure of Bandai Entertainment, Funimation announced at Otakon 2014 that they had licensed the anime television series.