Bill Rieflin (born William Rieflin) is a musician who has collaborated, toured and played with several bands and artists, among them, Ministry, R.E.M., Revolting Cocks, KMFDM, Swans, The Minus 5, Slow Music and an his own musical project called Pigface. Rieflin has also a career as a leader started with the album entitled "Birth of a Giant", published in 1999.