Jones's bluesy singing style developed out of the sound of American soul music. His early influences included blues and R&B singers Little Richard, Solomon Burke, Jackie Wilson and Brook Benton, as well as Elvis Presley. In March 1957 Jones married his high school girlfriend, Linda Trenchard when they were expecting a child together, both aged 16. The couple's son, Mark, was born in the month following their wedding. To support his young family Jones took a job working in a glove factory and was later employed in construction. Jones's voice has been described as a "full-throated, robust baritone". He became the frontman in 1963 for Tommy Scott and the Senators, a Welsh beat group. They soon gained a local following and reputation in South Wales.
The group recorded several solo tracks in 1964 with producer Joe Meek, who took them to various labels, but they had little success. Later that year, Decca producer Peter Sullivan saw Tommy Scott and the Senators performing in a club and directed them to manager Phil Solomon, but the partnership was short-lived. The group continued to play gigs at dance halls and working men's clubs in South Wales. One night at the Top Hat in Cwmtillery, Wales, Jones was spotted by Gordon Mills, a London-based manager who also originally hailed from South Wales. Mills became Jones's manager and took the young singer to London, and also renamed him Tom Jones, to exploit the popularity of the Academy Award winning 1963 film.
Eventually, Mills got Jones a recording contract with Decca. His first single, "Chills and Fever", was released in late 1964. It did not chart, but the follow-up, "It's Not Unusual", became an international hit after offshore pirate radio station Radio Caroline promoted it. The following year was the most prominent of Jones's career, making him one of the most popular vocalists of the British Invasion. In early 1965, "It's Not Unusual" reached No. 1 in the United Kingdom and the top ten in the United States. During 1965, Mills secured a number of film themes for Jones to record, including the themes for the film “What's New Pussycat?” (written by Burt Bacharach and Hal David) and for the James Bond film “Thunderball”. Jones was also awarded the Grammy Award for Best New Artist for 1966. In Hollywood, he met Elvis Presley for the first time who he recalls singing his song as he walked towards him on set.
In 1966, Jones's popularity began to slip somewhat, causing Mills to reshape the singer's image into that of a crooner. Jones also began to sing material that appealed to a wider audience, such as the big country hit "Green, Green Grass of Home". The strategy worked, and Jones returned to the top of the charts in the UK and began hitting the Top 40 again in the US. For the remainder of the decade, he scored a string of hits on both sides of the Atlantic, including "I'll Never Fall in Love Again", "I'm Coming Home", and "Delilah" which all reached No. 2 in the UK chart.
Jones performed in Las Vegas for the first time at the Flamingo, in 1967. His performances and style of dress became part of his stage act, and increasingly featured his open, half-unbuttoned shirts and tight trousers. He soon chose to record less, instead concentrating on his lucrative club performances. His shows at Caesars Palace were a knicker-hurling frenzy of sexually charged adulation and good-time entertainment. Women started throwing hotel room keys onto the stage. Jones and his idol Elvis Presley met in 1965 at the Paramount film stage, when Elvis was filming Paradise, Hawaiian Style. They became good friends, spending more and more time together in Las Vegas and duetting until the early hours at Presley's private Las Vegas suite. The friendship endured until Presley's death in 1977.