The agency secured the PR launch project brief following a competitive pitch process.
The appointment comes ahead of the global energy drinks company introducing the blueberry, cranberry and lime flavours - known as the blue, red and silver editions - early next year.
An agency source commented: 'Red Bull has a lot of loyal fans, but equally there are a lot of people who don't like the taste - this is about targeting them.'
Red Bull and John Doe both declined to comment.
