Hughes, who was in the running last year for the chairman's job at Channel 4 which went to Luke Johnson, currently holds a string of non-executive director roles. These include Vodafone, Reuters, Trinity Mirror, Gap and the Swedish Bank. She also sits on the advisory board of Bridgepoint Venture Capital.
Earlier in her career, she spent 10 years at Coca-Cola, becoming president of the UK & Ireland in 1992 at the age of 33. She stepped down for family reasons and since developed her career as a company director.
Hughes said: "As a passionate believer in responsible advertising I look forward to contributing to the important work of the Advertising Association."
The appointment is subject to the approval of the AA's council on April 14, but Hughes was invited by FitzGerald to succeed him and she has been nominated president-elect. FitzGerald retired as chairman of Unilever last September.
FitzGerald said that Hughes represents a new generation of senior business thinkers who can a breadth of marketing experience that will be of immense value to the communication business.
Andrew Brown, the AA's director-general, said: "The business is changing and faces many challenges that can only benefit from her input."
The Advertising Association is a federation of 26 trade bodies representing advertisers, agencies, the media and support services in the UK, including ISBA and the IPA.
It supported Ofcom's recent toughening up of alcohol advertising rules and its Food Advertising Unit, which provides information on advertising food to children, is a key player in the debate on the future of food advertising.
The FAU recently criticised the government for not engaging the advertising industry as a partner in drawing up the White Paper on public health.
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