William Geoffrey Steer is a British guitarist and co-founder of the extreme metal band Carcass. He is considered a pioneer and an essential contributor to grindcore and death metal due to his involvement in Napalm Death and Carcass, two of the most important bands of those genres. Presently he plays with Gentlemans Pistols, the reactivated Carcass and appeared as a live second guitarist for Angel Witch from 2011 to 2015.