Robert Pete Williams (March 14, 1914 – December 31, 1980) was an American Louisiana blues musician. His music characteristically employed unconventional structures and guitar tunings, 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).

Williams was born in Zachary, Louisiana, to a family of sharecroppers. He had no formal schooling, and spent his childhood picking cotton and cutting sugar cane. In 1928, he moved to Baton Rouge, Louisiana and worked in a lumberyard. At the age of 20, Williams fashioned a crude guitar by attaching five copper strings to a cigar box, and soon after bought a cheap, mass-produced one. Williams was taught by Frank and Robert Metty, and was at first chiefly influenced by Peetie Wheatstraw and Blind Lemon Jefferson. He began to play for small events such as Church gatherings, fish fries, suppers, and dances. From the 1930s to the 1950s, Williams played music and continued to work in the lumberyards of Baton Rouge.