Speaking with Britain's Autocar magazine, Audi R&D boss Wolfgang Dürheimer reportedly confirmed the new model, pointing to the Range Rover Sport as a key rival.
"We can go bigger than we have with the Q7, and we can all see that this sector is growing," Mr Dürheimer said.
"Audi has the biggest SUV in the group, and I don't see any reason to change that."
As with the expected Q2, Q4 and Q6 models, the Q8 will reportedly wear a tapered coupe-like roofline, giving it the profile to take on the Range Rover Sport in the style game.
Like the next-generation Q7, the top-shelf Q8 would likely be built on an extended version of the Volkswagen Group's MLB platform.
If earlier reports are to be believed, the Q8 will make its production debut sometime in 2017.