William Backer was an advertising executive best known for creating the Coca-Cola "Hilltop" commercial, which featured the song "I'd Like to Teach the World to Sing." The spot, an instant hit when it first aired in 1971, drew renewed attention when it was featured prominently in the final episode of the acclaimed drama series Mad Men.

During his heyday, Backer and his team created some of the most memorable ad slogans of the 1960s and 1970s. They included campaigns for Coke ("The real thing"), Miller Lite beer ("Everything you ever wanted in a beer — and less"), Campbell's soup ("Soup is good food") and many others.

Born in New York City, Backer moved with his mother to South Carolina at age six, shortly after the death of his father. He went on to serve in the Navy and graduate from Yale University, after which he started a jingle business.

He got his start in the ad agency world with an entry-level position at McCann-Erickson in 1953. He became creative director in 1978 and vice chairman in 1978. A year later he formed his own agency, Backer & Spielvogel, with colleague Carl Spielvogel. In 1986 the British conglomerate Saatchi & Saatchi bought the agency for a reported $56 million, with an additional $45 million paid over six years.

In retirement he settled in Virginia, where he owned a thoroughbred horse farm.

Backer died on May 13, 2016, in Warrentown, Virginia. He was 89.