His name is spelled in many different variations, such as Amen or Amon. To the Egyptians, he was Imen. To the Greeks, Ammon, who equated him with their supreme diety, Zeus. Amun is the King of Gods, but does not preside over the other Netjeru (Gods) to give them orders, but is just a supreme Netjer. He is often portrayed as a ram, goose, frog-headed man, or a handsome young man with a double-plumed crown. Amun's name means "That Which is Hidden", or "The Hidden One". His image was mostly painted blue, a symbol/color which represents invisibility; because of this common attribute, Amun became a god for those who were oppressed during the New Kingdom due to the knowledge and impartiality to himself. He also represented the winds, and all that could not be seen by mortals; a supernatural trait to many.

Amun was the state god of Kemet in the New Kingdom, which started with the 18th Dynasty, but he may have originated as a local diety in Khmun (Hermopolis) in Middle Egypt. His cult reached Waset (Thebes), where, by the time of Montuhotep I, during the 11th Dynasty, he became the patron god of the Pharaohs, and he gave his sons, these Pharaohs, the power to receive victory over their enemies. At that time, he was already identified with the sun-god Ra of On (Heliopolis), and was received as a national god as Amun-Ra. When represented as a human, or sometimes with a ram's head, he was worshipped as part of the Theban Triad alongside his consort Mut, and their youthful son Khonsu, or Khons. A ram was kept at Karnak as a living incarnation of the god. The goose was also sacred to him. While in the form of a ram, he was the god of fertility and reproduction, and the creative power of life that ensured the harvest. Waset itself became known as Nut Amun (The City of Amun), or just Nut (The City). Conquering pharaohs who bore the name Amenhotep were the reputed sons of Amun. Like Atum, Amun was believed to have given birth to himself and to have formed all other gods at the Primeval Mound of Men-Nefer (Memphis). Eventually, Amun retired to the heavens where he dwelt as the god Ra. His temple at Waset received vast wealth through foreign tributes and donations by victorious Pharaohs, like Ahmose and his successors.

Until the Middle Kingdom, Amun was just a local god in Waset, but the Thebans soon established their sovreignity over all of Kemet, thus making Amun a prominent diety, and by the 18th Dynasty, he had become the King of the Gods.

Usually, the strength of a god would add luster and prominence to the Pharaoh, but when Amun grew in power, his priests became powerful in wealth and influence, and they often tried to enter politics. To attain such popularity, Amun adopted many of the same traits as Ra. According to Budge, by the 19th-20th Dynasties, Amun was thought of as "an invisible creative power which was the source of all life in heaven, and on earth, and in the great deep, and in the Underworld, and which made himself manifest under the form of Re". The cult of Amun-Ra became very powerful, and its priests gained power that rivaled that of Pharaoh's. The largest temple dedicated to him is in Karnak. Amun's priests clinged to a concept that he was part of a triad with Ptah and Ra, or as a single god of whom all other gods were manifestations. Around 1075-950 BC, Theban priests of Amun ruled over Kemet. Amun became a universal god and intervened in affairs of state through oracles. One of the most famous of these oracles being The Siwa Oasis. Queen Hatshepsut found many supporters who were Amun's priests, and she even went as far to claim her right as Pharaoh by claiming that Amun was her father. Hatshepsut made another political maneuver by building another temple in his honor in Deir el-Bahri. Despite Amun's political ascension, he still remained popular among common folk and the poor of Kemet. He was often referred to as "The Vizier of the Poor". He protected the weak from the strong. He upheld justice; he was the god for those who were opressed, but, in order to receive favors from him, you must demonstrate your worthiness or confess your sins. During the time the Hyksos ruled Kemet (1630-1523 BC), Theban princes still worshipped Amun. After the victory of the Thebans over the Hyksos, in the reign of Ahmose, the rising of a new empire began, and Amun became stronger. This a came to a slow halt during the reign of Thutmosis IV, and by the time of Amenhotep IV, the royal house was worshipping a purer form of the sun, known as the Aton. Amenhotep went as far as changing his name to Akhenaton, or "Servant of the Aton". Akhenaton erased the name of Amun everywhere. Amun's temples were demolished, and the capitol moved from Waset to Aketaton. No one is sure what happened to Akhenaton or his famous queen Nefertiti, but some believed that the priests of the old god instigated their upheaval. The worship of Amun was gradually restored under the rule of such Pharaohs as Tutankhamen, Horemheb, and Aye. The capitol was moved back to Waset, but the people of Kemet began focussing their worship more on the Osirian family. During the later 22nd and 23rd Dynasties, Assyria invaded Kemet and Waset was sacked, but this did not crush the cult. Tanis had become a second centre for worship. When the Hittites invaded, they were accepted by the Egyptian government because they acknowledged the cult of Amun. Resistance to foreign occupation became strongest in Waset. The Ptolmaic Dynasty survived in Kemet by supporting the temples. When Ptolemy IV Philopator came to rule, rebellions broke out in Upper Egypt, and Ptolemy IX Soter II sacked Waset. Amun's cult suffered from a severe blow. The Theban temples were eventually damaged in 27 BC by devastating earthquakes.