Zao () is an American metalcore band founded in Parkersburg, West Virginia, and later relocated to Greensburg, Pennsylvania. Founded in March 1993, Zao has hosted several musicians and endured numerous roster changes to the point where no original members remain. Former drummer Jesse Smith, vocalist Dan Weyandt, and guitarists Scott Mellinger and Russ Cogdell are seen by some fans as the "core" of Zao, with the current line up being the longest running in the band's history.

For a time, the band featured Christian themes in their music and was regarded as a Christian band, however this theme was eventually met with debate among the members and the band currently no longer considers themselves a "Christian band" with only bassist Martin Lunn identifying as a Christian.

To date, Zao has released 11 full-length albums, 9 EPs or splits, a two-disc DVD documentary and embarked on numerous concert tours, garnering a limited but global fan base and earning critical praise in the process.