Izayoi (written: 十六夜 lit. "Sixteenth Night"), is a Japanese family surname. Fictional people with the surname include:
Izayoi, a character from the Japanese manga series Inuyasha Izayoi, alter ego of playable character Tsubaki Yayoi from the BlazBlue fighting game series. Sakamaki Izayoi, the main protagonist from the Japanese light novel series Problem Children are Coming from Another World, aren't they? Sakuya Izayoi, a character in Embodiment of Scarlet Devil from the video game series Touhou Project Miku Izayoi, a character from the a Japanese light novel series Date A Live Kyuemon Izayoi, also known as Kyuemon Shingetsu Kibaoni, a secondary villain from the 39th season of Super Sentai Series, Shuriken Sentai Ninninger Sonosuke Izayoi, a character from the second anime series based in the Danganronpa video game Danganronpa 3: The End of Hope's Peak Academy Nonomi Izayoi, a character from the mobile game Blue Archive Riko (also spelled Liko), a character from the anime series Witchy Pretty Cure! who takes on the last name Izayoi in the Non-Magical World.