Davies, who takes up his new role in the autumn, is still at EHS Brann in London, where he has been responsible for clients including British Gas, Tesco Clubcard and Peugeot.
Prior to joining EHS, Davies, who started his career at WWAV in London, co-founded integrated marketing agency Junction Group and also worked at Tullo Marshall Warren.
He takes over from the current managing director Allan Freeman, who will leave at the end of the year. Freeman does not currently have a new job to go to.
Chris Gordon, WWAV Rapp Collins group chairman and chief executive, said: "Allan has decided to move on and goes with our thanks and best wishes. He will work alongside Nick until the end of the year to ensure a smooth transition."
He added: "I am delighted to welcome Nick back. His all-round experience and proven leadership skills are exactly what is required to take WWAV West on to the next stage of its development."
Based in Bristol, WWAV Rapp Collins West has 30 staff and a client list that includes Chelsea Building Society, British Red Cross and Gala Bingo.
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