William Graziadei is an American musician who is best known as the lead vocalist, rhythm guitarist, and founding member of Biohazard. Graziadei is also the rhythm guitarist and backing vocalist of the band Powerflo and frontman for BillyBio, which is his latest solo project. In addition, he is the former rhythm guitarist for Suicide City. Graziadei also performed as part of the Roadrunner United project in 2005 as well as Blood for Blood in 2010.