Rosario + Vampire (Japanese: ロザリオとバンパイア, Hepburn: Rozario to Banpaia) is a Japanese manga series written and illustrated by Akihisa Ikeda. The story revolves around Tsukune Aono, a boy who inadvertently enrolls in a boarding school for monsters. He quickly befriends Moka Akashiya, a vampire who soon develops an obsession with his blood, and later meets other monster girls who soon take a romantic liking to him. The manga was serialized in Shueisha's shōnen manga magazine Monthly Shonen Jump from April 2004 to June 2007, when the magazine ceased its publication. An extra chapter was published in Weekly Shōnen Jump in September 2007. The chapters were collected in ten tankōbon volumes.

A sequel, titled Rosario + Vampire: Season II, was serialized in Jump Square from November 2007 to February 2014. An epilogue chapter was published in Jump SQ.19 in April 2014. The chapters were collected in 14 tankōbon volumes. Both manga series were licensed in North America and in the United Kingdom by Viz Media, and in Australia and New Zealand by Madman Entertainment. The series also spanned three CD dramas, two visual novels, a novel adaptation, and two internet radio shows.

A 13-episode anime adaptation aired between January and March 2008. A second season of the series, Rosario + Vampire Capu2, aired between October and December 2008. The anime was licensed in North America by Funimation (later consolidated into Crunchyroll), who released both seasons in December 2011. The anime is also licensed in Australia and New Zealand by Madman Entertainment, who released both seasons in 2012.

Tsukune Aono is an average teenager who is unable to get into any local high schools due to his poor grades. As a last-ditch effort to secure his education, his parents enroll him in a private school called Yokai Academy, which he discovers is a boarding school for monsters. The school teaches monsters how to coexist with humans, including disguising them as them, but any real humans found on campus are to be killed. Although he fears for his life, Tsukune befriends a beautiful vampire girl named Moka Akashiya, who enjoys his company and especially the taste of his blood. During a fight with a school bully, Tsukune accidentally removes the rosario around Moka's neck and discovers that she transforms into a powerful vampire with a completely different personality.

Because of Moka, Tsukune decides to stay at Yokai. He befriends formerly antagonistic students, including succubus Kurumu Kurono and child prodigy witch Yukari Sendo. They join the school's Newspaper Club and wind up fighting a variety of students and teachers, who use their monstrous powers to bully or to control one or more of the members for their own selfish or destructive ends. On a club trip to the human world, they meet a witch, Ruby Tojo, who defends a field of sunflowers from being torn down by developers. They meet Mizore Shirayuki, a snow fairy student who becomes Tsukune's "stalker". A group of "Monstrels" harass the club. Ruby, having recovered from injuries, joins the school's staff as the Headmaster's assistant. An evil group called the Anti-Schoolers threaten to break down the barrier between the human and monster worlds. When Tsukune's cousin manages to sneak onto the school grounds, the club has a hard time keeping the monster school a secret. When the school is temporarily closed because of damage, Tsukune returns home to the human world only to have Moka, Kurumu, Yukari, and Mizore follow him and hide in his room.

In Rosario+Vampire: Season II, Moka's younger half-sister Koko Shuzen enrolls. She, Ruby, and Mizore join the Newspaper Club. On an excursion to Mizore's homeland, they learn of a dangerous organization called Fairy Tale, which seeks to destroy the human world. The Newspaper Club visits the human world where they meet San Otonashi, a former club member, and run into trouble with adversaries from Fairy Tale's 7th Branch office. Chinese transfer student Fangfang Huang tries to recruit Tsukune to join his mafia family. When Moka spends a school day as her inner personality, she is unable to return to the seal, so the Newspaper Club heads to China to get her Rosario fixed.

In Hong Kong, Tsukune and the gang learn the truth about Moka's identity: she was infused with First Ancestor blood by her mother Akasha Bloodriver, who sacrificed herself to protect them from Alucard, the original First Ancestor vampire. Moka's eldest half-sister Aqua infiltrates the Huang manor and captures Moka to bring to Fairy Tale, which suspects that Moka is the key to reviving Alucard. While his friends train their powers, Tsukune has his body altered by Tohofuhai to handle the upcoming challenges.

Tsukune and the gang infiltrate the Hanging Garden: a sky fortress that serves as Fairy Tale's headquarters. They face opposition from their leader and matriarch of the Shuzen family Gyokuro Shuzen, who sends the leaders of the Fairy Tale Branches after them for a series of fights. The group eventually reaches Moka, but must face her half-sisters Aqua and Kalua. Gyokuro snatches Moka's rosario in order to control Alucard. A character called the Masked King reveals himself to be a clone of Alucard's original vampire form. He reveals that he has manipulated both Fairy Tale and its opposition to determine whether the rosario could control him, and then merges with his monster self, who goes on a rampage in Tokyo.