Is there an age limit for UFC?

Yes. If you are talking about the minimum age limit to fight in the UFC, then it would be 18 because UFC is a combat sport where people can get hurt and injured. So, they would not allow minors to compete. If you are asking about the upper age limit, then, frankly speaking there is no upper limit. As long as a fighter is willing and medically able to fight, he can stay a fighter in the UFC.