Kayo may refer to:
- KAYO (FM), radio station licensed to Wasilla, Alaska
- Kayo (music), Korean term for pop music
- Kayo, member of the new wave band Polysics, whose name is taken from the Korean term
- Kayo, popular slang for the condiment created by mixing tomato ketchup and mayonnaise. Portmanteau of ketchup and mayo.
- Kayo Hatta, American film director
- Kayo Matsuo, Japanese actress
- Kayo Shekoni, Swedish singer, dancer, and actress
- Kayo Yamaguchi, Japanese painter
- Kayo Yuunagi, Japanese voice actress
- Kayo (Nigerian name)
- Kayo, the title character's little brother in the comic strip Moon Mullins
- Kayo, a fictional character in the He-Man universe
- Kayo the Hutt, a Star Wars character
- Tin-Tin Kyrano, Thunderbirds character also known as "Kayo" in the 2015 series.
- Hinazuki Kayo, a main character in the manga and anime Boku Dake ga Inai Machi