Newman was born near Big Mamou, Louisiana. As a child, he listened more to Gene Autry than to the Cajun music of the area, but had a number of Cajun songs in his repertoire when, as a teenager, he joined Chuck Guillorry’s Rhythm Boys. He recorded a few unsuccessful sides for J.D. Miller’s Future label in the 1940s, but Miller persuaded Fred Rose in Nashville, Tennessee to give the young singer an opportunity. In 1953, he was signed to Dot Records and the following year recorded "Cry, Cry Darling," which reached number four on the country chart.
His recording success led the Louisiana Hayride in Shreveport, Louisiana, to hire him as a regular performer. His next four records all reached Top 10 status, and in 1956 he was invited to become a member of the Grand Ole Opry. That following year he released his biggest hit, "A Fallen Star," which spent two weeks at number two and also entered the Top 25 of the Billboard Hot 100 pop chart.
As an established artist, he began to integrate his Cajun influences into his music and recorded "Alligator Man," which was a top 25 record and continues to be his theme song at the Opry. In 1963, he released another top 10 Hit, "The D.J. Cried." His final hits came in 1965 and 1966 with "Artificial Rose" and "Back Pocket Money." When his commercial popularity declined he returned to Cajun music, forming his Cajun Country band and taking the high energy fiddle- and accordion-based music of his native Louisiana to fans around the world. In 1976, his recording of the Cajun French song, "Lâche pas la patate" ("The Potato Song") earned gold record status in Canada. In 1991, Newman and Cajun Country earned a Grammy nomination for their album, Alligator Man.
In 2000, he was inducted into the North American Country Music Association’s International Hall of Fame and in 2004 was inducted into the Cajun Hall of Fame. He is also honored in the Cajun Music Hall of Fame in Lafayette, Louisiana.
Newman and his wife made their home on their 670-acre (2.7 km2) ranch outside of Nashville in Murfeesboro. He continues to tour and appears regularly at the Grand Ole Opry. In 2006, he joined a select group of entertainers who have marked 50 years of Opry membership.