Koizumi Yakumo (小泉 八雲, 27 June 1850 – 26 September 1904), born Patrick Lafcadio Hearn (; Greek: Πατρίκιος Λευκάδιος Χέρν, romanized: Patríkios Lefkádios Chérn), was a Greek-Japanese writer, translator, and teacher who introduced the culture and literature of Japan to the West. His writings offered unprecedented insight into Japanese culture, especially his collections of legends and ghost stories, such as Kwaidan: Stories and Studies of Strange Things. Before moving to Japan and becoming a Japanese citizen, he worked as a journalist in the United States, primarily in Cincinnati and New Orleans. His writings about New Orleans, based on his decade-long stay there, are also well-known.

Hearn was born on the Greek island of Lefkada, after which a complex series of conflicts and events led to his being moved to Dublin, where he was abandoned first by his mother, then his father, and finally by his father's aunt (who had been appointed his official guardian). At the age of 19, he emigrated to the United States, where he found work as a newspaper reporter, first in Cincinnati and later in New Orleans. From there, he was sent as a correspondent to the French West Indies, where he stayed for two years, and then to Japan, where he would remain for the rest of his life.

In Japan, Hearn married Setsuko Koizumi with whom he had four children. His writings about Japan offered the Western world a glimpse into a fascinating culture largely unknown in the West at the time.