xxxHolic (stylized as ×××HOLiC; pronounced "Holic") is a Japanese manga series written and illustrated by the manga group Clamp. The series, which crosses over with another Clamp work, Tsubasa: Reservoir Chronicle, revolves around Kimihiro Watanuki, a high school student who is disturbed by his ability to see the supernatural, and Yūko Ichihara, a powerful witch who owns a wish-granting shop. When Watanuki asks Ichihara to remove his ability to see spirits, she grants it on the condition that he pay for his wish by working for her. Clamp created xxxHolic to link the supernatural and fantasy series.

xxxHolic was serialized in Kodansha's seinen manga magazine Weekly Young Magazine periodically from February 2003 until March 2010. It then moved to the shōnen manga magazine Bessatsu Shōnen Magazine in June 2010, where it ended serialization in February 2011; its chapters were collected in 19 tankōbon volumes. A sequel, xxxHolic: Rei, started in 2013. It was first published in the United States by Del Rey Manga and in the United Kingdom by Tanoshimi in 2004, then was later published in a series of omnibuses by Kodansha Comics as of 2014. In 2005, Production I.G adapted the manga into an animated film, which was followed by two anime television series, and various original video animations (OVAs). Funimation licensed the film and the first TV series in North America, and released both of them in DVD as well as Blu-ray Disc. A light novel and a video game have also been released based on the series.

The manga has been well received by both Japanese and English readers and has appeared in various rankings of bestselling books. Critics have generally praised the series for its illustrations and its portrayal of supernatural elements.