Steve Di Giorgio (born November 7, 1967) is an American musician of Italian descent. Di Giorgio has played bass guitar in heavy metal and death metal bands such as Death, Autopsy, Control Denied, Ephel Duath, Obscura, Artension, Faust, Memorain, Painmuseum, Suicide Shift, Soen, Vintersorg, Dragonlord, Iced Earth, Sebastian Bach, Obituary, and is a founding member of Sadus. He is a founding member of the jazz band Dark Hall and has played bass in other bands such as Testament, Futures End, Synesis Absorption, Mythodea, Charred Walls of the Damned, Anatomy of I, Gone in April, and Spirits of Fire. Along with his bass duties in Sadus he also plays keyboards. In October 2019 he founded the fusion-world-metal group Quadvium with fellow fretless bass player Jeroen Paul Thesseling. Within his genre, Di Giorgio is respected for his highly technical playing skills. He is also widely credited with being the first bassist to bring fretless bass playing into the heavy/extreme metal genre, and often plays bass by using his fingers instead of a pick. Di Giorgio has stated that his main influences as a bassist are Geddy Lee, Chris Squire, Geezer Butler, Steve Harris, Stanley Clarke, Jaco Pastorius, Billy Sheehan, Dave Pegg and Charles Meeks.