Billy Graziadei (born July 28, 1969) is an American musician who is the rhythm guitarist, one of the vocalists and the sole continuous founding member of the hardcore/metal band Biohazard.

[1] He is also the rhythm guitarist and backing vocalist of the band Powerflo and frontman for BillyBio, his latest solo project.

[11] Through their music, the band has promoted tolerance, opposed racism, spoken out against drug abuse all while speaking about the realities of inner city life.

[17] Graziadei briefly formed a trip hop project named Blu with Jenifer Bair of the Ohio band Hilo.

In 2004, Graziadei started Suicide City with Groovenics singer Karl Bernholtz, Groovenics/Ghost Fight guitarist A. J. Marchetta, Kittie bassist Jennifer Arroyo and New York drummer Danny Lamagna.

[19] In December 2005, Graziadei and Evan Seinfeld performed Biohazard's "Punishment" with Dino Cazares of Fear Factory, Andreas Kisser of Sepultura, Adam Duce of Machine Head and Joey Jordison of Slipknot.