He replaces Avril Gallagher, who is leaving Starcom to head the global Vodafone account at OMD.
Benoit was previously global group media director at Universal McCann SF and previously regional client services director at Universal McCann EMEA.
Iain Jacob, president of global innovation and executive director for Europe, Middle East and Africa at Starcom MediaVest Group, said: "Starcom MediaVest Group is leading the market in transforming the media agency model and a crucial element of this has been substantial further investment in digital, technology, data and research.
"In Geraud we have a very rare and powerful combination of deep expertise in these areas along with extensive time working on global FMCG brands. This appointment is yet another positive step forward in our continued drive to increase our digital offering and help clients maximise benefits."
Benoit has worked on several accounts including Microsoft, Coca Cola, L'Oreal, Nestle, UPS, GlaxoSmithKline and Boots.
Most recently, he was responsible for the management of Microsoft’s Xbox account across 37 markets, including social media activity around the roll out of the Microsoft Kinect gaming brand.
Benoit said: "The chance to work with a client like Procter & Gamble is too good to miss– they are an undisputed leader in media globally. I look forward to using my experience to contribute to the strategic vision and success of SMG over the coming years."