Sampson, 37, will report to Graham Duff, managing director designate of ITV Sales, and will be responsible for ITV's client team, as well as business-to-business and trade marketing. He will also help ITV assume a 'brand leader' role in working with other TV companies to promote the medium.
His appointment completes ITV's senior sales team, which includes ITV director of sales Gary Digby, director of sales operations Jill Kerslake, director of knowledge management Andy Bagnall and director of cinema Debbie Chalet.
He joins after 12 years building the RAB into one of the most respected media marketing organisations in the UK.
Sampson said: "This is an excellent opportunity to recalibrate the relationship ITV has with advertisers."