Onmyōji (陰陽師) is a series of historical fantasy short stories and novels written by Japanese author Baku Yumemakura. It follows the story of a fictionalized version of the Heian period onmyōji Abe no Seimei, a master in onmyōdō, a traditional Japanese form of cosmology.

Baku Yumemakura is a Japanese science fiction and adventure writer. His works have sold more than 20 million copies in Japan spread across more than 280 titles and adapted into a variety of formats including feature films, television shows, movies and comic books.