Daniel Lewis Williams is an American operatic basso profundo.

Williams grew up in Billings, Montana and appeared in operas and concerts as boy soprano in the Western United States. After his voice changed, he appeared frequently in musicals and won the International Kiwanis Talent Contest in New York City at 17 for his performance of "Ol' Man River" from Show Boat. He graduated with a B.A. in theater from the University of Utah in Salt Lake City. He continued his studies at the Staatliche Hochschule für Musik in Munich, Germany, studying with Ernst Haefliger, Kurt Böhme, and Kurt Moll.

He began his professional career with the Trier, Germany opera, with regular engagements with the Landestheater in Kiel and the theater in Krefeld. In 1989, he became the regular bass at the Deutsche Oper am Rhein in Düsseldorf.

He has had a far-flung international career, appearing in many of the major opera houses of Europe and the United States, as well as in Japan. His signature roles are Baron Ochs von Lerchenau in Richard Strauss's Der Rosenkavalier (a role that he has performed in over 22 productions all over the world), Sarastro in Mozart's The Magic Flute, and King Philip in Giuseppe Verdi's Don Carlos, but he sings many roles that are rarely attempted by other basses because of his tremendous range. He has recently added Strauss's Die Schweigsame Frau to his repertoire, and in June 2005, he will be singing in a production of Strauss's Daphne in the newly renovated La Fenice theater in Venice, Italy.

He appears on a DVD of Rosenkavalier recorded live at the Teatro Massimo in Palermo which is in general distribution. He has also recorded a CD with his daughter Judith Williams, a presenter on the German shopping channel, called Träume. This CD is available on the shopping channel, but is not yet in general distribution.

Williams is married to the former Gaye Hicks, and they have three daughters. They make their home in Konz, near Trier, Germany.