After winning a competitive pitch, Adam & Eve/DDB will develop creative work for the insurer to run in markets around the world that include Asia and Canada as well as Europe.
Abbott Mead Vickers BBDO was the UK incumbent but did not repitch for the business.
Jan Gooding, Aviva's group brand director, said: "We are starting to maximise our potential as one of only a few insurers in the world able to provide our customers with the benefit of our offering across life, general and health insurance, retirement and investments.
"This gives us a clear competitive advantage – especially in a digital world. It’s time to reflect this in our trusted and respected brand. Adam & Eve/DDB impressed us with its fresh thinking, grasp of the task and vision for what is possible as we move the Aviva brand forward."
Adam & Eve/DDB beat CHI & Partners in the final stage of the process, which also involved DLKW Lowe, Grey London and J Walter Thompson.
James Murphy, the chief executive of Adam & Eve/DDB, said: "We were inspired by Aviva’s clear purpose for their customers and the evolution of their brand, which plays such a meaningful role in their customers’ lives."
Aviva's global media agency, ZenithOptimedia, is not affected by the appointment.