Shingeki no Kyojin

          ~is a Japanese manga series written and illustrated by Hajime Isayama. The series began serialization in Kodansha's Bessatsu Shōnen Magazine on September 9, 2009, and has been collected into 13 tankōbon volumes as of April 9, 2014. It is set in a world where humanity lives inside cities surrounded by enormous walls as a defense against the Titans, gigantic humanoid creatures who devour humans seemingly without reason. The story initially centers on protagonist Eren Yeager, his adoptive sister Mikasa Ackermann, and their childhood friend Armin Arlert, who join the military to get revenge for the death of Eren's mother at the hands of the Titans. As the story progresses, the truth about the Titans begins to arise and the story shifts to one about political subterfuge, all in an attempt to hide or reveal the truth to the public.

A spin-off light novel series began in December 2011, and has received a manga adaptation. Two additional spin-off manga series are also being serialized, and a television anime adaptation produced by Wit Studio and Production I.G aired in Japan on MBS between April and September 2013. Four video game adaptations developed by Nitroplus staffers in collaboration with Production I.G were announced to be released as bonus content for the third and sixth volumes of the Blu-ray Disc release of the anime, with another game developed by Spike Chunsoft for the Nintendo 3DS. A live action film adaptation is also in production and set to premiere in 2015. Attack on Titan and all three spin-off manga are published in North America by Kodansha Comics USA, while the novels will be published by Vertical. The anime has been licensed by Funimation for North America, by Manga Entertainment for the United Kingdom, and by Madman Entertainment for Australasia.

Attack on Titan has become a commercial success, with 40 million volumes in circulation as of July 2014. The release of the anime also saw a boost in the series' popularity, with it having received critical acclaim for its atmosphere and story. Although it also gained fame in neighboring Asian countries, the series' themes have been a subject of controversy.