There are a variety of religious beliefs surrounding the answer to this question, so it is difficult to provide a single, definitive answer. In general, most religions believe that there is some sort of higher power or creator who is responsible for the existence of the universe and everything in it. This higher power is often referred to as God or the Creator.
There are many different theories about who created God, and how exactly God came into existence. Some believe that God has always existed, and was never created by anyone or anything. Others believe that God was created by another being, such as another god or goddess. Still others believe that we humans created God, either through our own individual imaginations or collectively as a society.
Ultimately, there is no way to know for sure who created God, if anyone did at all. This is an area where faith must play a role; each person must decide for themselves what they believe about the origins of the divine.