Whitman was born in Tampa, Florida, as Ottis Dewey Whitman, Jr. on January 20, 1923. Growing up, he liked the country music of Jimmie Rodgers and songs of Gene Autry, but he did not embark on a musical career of his own until the end of World War II, after he had served in the South Pacific with the United States Navy.
Whitman, a self-taught left-handed guitarist, was right-handed, but he had lost almost all of the second finger on his left hand in an accident. He worked at a Tampa shipyard while developing a musical career, eventually performing with a band known as the Variety Rhythm Boys. Whitman's first big break came when talent manager "Colonel" Thomas Parker heard him singing on the radio and offered to represent him. Signed with RCA Records, he was billed as "the cowboy singer Slim Whitman" and released his first single in 1948. He toured and sang at a variety of venues, including on the radio show Louisiana Hayride.
At first, he was not able to make a living from music and kept a part-time job. That changed in the early 1950s after he recorded a version of the Bob Nolan hit Love Song of the Waterfall, which made it into the country music top ten. His next single, "Indian Love Call," was even more successful, reaching number 2 in the country music charts and appearing in the pop music charts top ten in the US.
A yodeller, Whitman avoided the "down on yer luck buried in booze" songs, preferring instead to sing laid-back romantic melodies about simple life and love. Critics dubbed his style "countrypolitan," owing to its fusion of country music and a more sophisticated crooning vocal style. Although he recorded many western tunes, love and romance songs figured prominently in his repertoire.
In 1955 in the United Kingdom, he had a No.1 hit on the pop music charts with "Rose Marie." With 19 weeks in the chart and 11 weeks at the top of the UK Singles Chart, the song set a record that lasted for 36 years. In 1956 he became the first ever country music singer to perform at the London Palladium. Soon after, Whitman was invited to join the Grand Ole Opry, and in 1957, along with other musical stars, he appeared in the film musical Jamboree. Despite this exposure, he never achieved the level of stardom in the United States that he did in Britain, where he had a number of other hits during the 1950s. Throughout the early 1970s, he continued to record and was a guest on Wolfman Jack's television show The Midnight Special. At the time, Whitman's recording efforts were yielding only minor hits.
In 1979, Whitman produced a TV commercial to support Suffolk Marketing's release of a greatest hits compilation titled All My Best, which went on to be the best-selling TV-marketed record in music history, with almost 1.5 million units sold. Just For You (also under the Suffolk umbrella), followed in 1980, with a commercial that claimed Whitman "was number one in England longer than Elvis and The Beatles." The Best followed in 1982, with Whitman concluding his TV marketing with Best Loved Favorites in 1989 and 20 Precious Memories in 1991.
The TV albums made Whitman (briefly) a household name in America for the first time in his career, resulting in everything from a first-time appearance on The Tonight Show starring Johnny Carson to Whitman being spoofed in a comic skit on SCTV with him (played by Joe Flaherty) starring in the Che-like male lead in an Evita-like Broadway musical on the life of Indira Gandhi. More importantly, the TV albums gave him a brief resurgence in mainstream country music with new album releases on major labels and a few new singles making the country chart. During this time he toured Europe and Australia with moderate success.
In late January 2008, a false rumor of his death spread through the internet, believed to have been started by an erroneous report posted on the Web site of the Nashville Tennessean newspaper. Country singer George Hamilton IV even dedicated and sang a hymn in Whitman's honor at a concert appearance.
He sold in excess of 120 million records.