Sanjo is a style of traditional Korean music, involving an instrumental solo accompanied by drumming on the janggu, an hourglass-shaped drum.

Sanjo was first developed around 1890 by Kim Chang-jo (1865-1920), for the gayageum. Thereafter, it was expanded to other traditional Korean instruments, including the geomungo and Korean flutes. Its early development was informed by other genres of traditional music, including pansori, sinawi, and the performances of Korean shamanism.

Daegeum sanjo, played on the daegeum (a traditional Korean transverse flute) was developed in the 1920s. It has since become one of the most popular forms of sanjo. Its leading practitioner today is Yi Saenggang.

Sanjo is traditionally identified as a form of minsogak, or folk music.