The concept of a “supreme god” depends entirely on religious, philosophical, and cultural perspectives. Across the world’s major belief systems, there is no single universally accepted answer, but rather several primary figures.

• Abrahamic Religions (Monotheism): In Judaism, Christianity, and Islam, the supreme and only God is the singular creator of the universe. He is known as Yahweh in Judaism, God in Christianity, and Allahin Islam. 
• Hinduism: Views vary by tradition. Many consider Brahman—the ultimate, formless, and infinite reality—as the supreme cosmic spirit. However, major denominations also have distinct supreme deities, such as Vishnu (Vaishnavism), Shiva (Shaivism), or the Goddess Shakti (Shaktism). 
• Greek & Roman Mythology (Polytheism): In ancient mythology, Zeus (Greek) or Jupiter (Roman) reigned as the king of the gods and ruler of the sky and thunder. 
• Other Cultural Pantheons: Ancient Egyptian mythology elevated Ra (the sun god) and later Amun to supreme status. In Norse mythology, Odin is often considered the all-father and chief of the gods. 

Because the ultimate truth is subjective, the answer changes depending on the specific belief system or philosophy you are exploring.

Would you like to explore the supreme god of a specific religion or culture, or are you interested in the philosophical differences between polytheism and monotheism?