Wrenn, who will move from London to CNN's Atlanta headquarters, will be the leading executive over all of CNN's digital assets outside of the US, overseeing editorial direction.
He will also work with colleagues across CNN.com's domestic operation and in Turner International to manage the growth of the business through the development of new products and services.
Wrenn will report to Tony Maddox, executive vice president and managing director of CNN International.
Maddox said: "As we continue to grow and develop our digital assets, Nick's experience and leadership will be invaluable.
"Our digital services are playing an increasingly important part in the growth of CNN International and this new position ensures that they will be leveraged and incorporated into our current business appropriately."
Wrenn has been with CNN since 2000. He joined as a senior editor for the international edition of and then became managing editor for CNN's operations in Europe, Middle East and Africa in 2003.