As well as spending more than three decades in the industry, he also served as a Conservative MP for 22 years and was a key figure behind Margaret Thatcher's challenge for the party's leadership in 1975.
An Oxford graduate and economics lecturer, Shelton began his advertising career in 1952 with Colman Prentice & Varley, the agency that ran the Tories' 1959 election campaign.
After running CPV's overseas operations, he was appointed as the managing director of Grosvenor Advertising in 1969.
In 1974, he began a seven-year spell as the chairman of the newly formed Fletcher Shelton Delaney, which later became Delaney Lund Knox Warren & Partners.
Winston Fletcher, who was Fletcher Shelton's managing director, said: "Bill was very charming, a good strategic thinker and very sharp. His problem was that he wanted to do too many things at once and his real love was politics rather than advertising."