Robert Pete Williams (March 14, 1914 – December 31, 1980) was an American Louisiana blues musician. His music characteristically employed unconventional blues tunings and structures, and his songs are often about the time he served in prison. His song "I've Grown So Ugly" has been covered by Captain Beefheart, on his album Safe as Milk (1967), and by The Black Keys, on Rubber Factory (2004). He was discovered in Louisiana State Penitentiary, by ethnomusicologists Dr Harry Oster and Richard Allen, where he was serving a life sentence for shooting a man dead in a local club in 1956, an act which he claimed was in self-defense. Oster and Allen recorded Williams performing several of his songs about life in prison, and pleaded for him to be pardoned. Under pressure from Oster, the parole board issued a pardon, and commuted his sentence to 12 years. By 1965, he was able to tour the country, and in 1966 he also toured Europe. His most popular recordings included "Prisoner's Talking Blues" and "Pardon Denied Again". Williams has been inducted into the Louisiana Blues Hall of Fame. Williams had slowed down his work schedule by the late 1970s, largely due to his age and declining health. Williams died in Rosedale, Louisiana on December 31, 1980, at the age of 66.