Senior will take on the new role from next year, amid a management shake-up of Publicis Groupe.
Senior, who has been UK chief executive of SSF Group since it was created in 2007, took on the role of EMEA chief executive of Saatchi & Saatchi in 2010, while Magnus Djaba took the helm of the UK agency in May this year.
Kevin Roberts, chief executive of Saatchi & Saatchi Worldwide will become executive chairman of Saatchi & Saatchi/Fallon from next year and will take on the role of head coach of Publicis Groupe.
He will step down from the management board in 2016, alongside Publicis boss, Maurice Levy.
Chris Foster, currently Saatchi & Saatchi Asia Pacific chairman and regional chief executive will move to chief operating officer at the same time.
Meanwhile, in a series of far-reaching organisational changes, Razorfish and Rosetta are to be combined under the new Razorfish Global brand. Tom Adamski, Current Chief executive of Rosetta will fill that role for the new entity.
DigitasLBi Luke Taylor, and Adamski will report directly to the Groupe chairman and chief executive.
Rishad Tobaccowala is appointed chief strategist of Publicis Groupe and will lead strategic thinking around the business’ digital development.
Robert Senior, Tom Adamski, Axel Duroux, Luke Taylor and Leo Burnett chief creative officer, Mark Tutssel and Jean Francois Valent are joining the current line-up of P12, the Groupe’s strategic consulting and operational coordination committee.
Elsewhere in the Groupe, VivaKi chief executive, Frank Voris, is promoted to chief executive of Re:sources with overall responsibility for the Groupe’s shared service centres and internal IT. He will also lead Prodigious, the Groupe’s production platforms.