In ancient times, when mythological elements came to the fore, people sanctified many elements of nature and gave them divine qualities, thus the concept of cult emerged. The moon, which indirectly reflects the light it receives from the sun and replaces the sun at night, has gained a sacred character from the ancient ages since it is a source of light from the sky. After the sun, the largest and brightest celestial body in the sky, the moon, which has grown and shrunk, has been identified with the cycle of birth and death. Also, the fact that the moon is visible only in the dark, every day rises and sinks, is associated with the other world and death and resurrection. In the periods when the relationship between the earth and the moon was not known, the worship of the moon, which was given a divine nature, started in Sumerian civilization and spread through Hittite civilization and spread to all societies of the first age. Since the movement of the moon in the sky is in different phases, since the first ages, there is the belief of taking action according to the movements of the moon. Entering the battle, winning and defeating according to this movement was always evaluated. As in the mythology of each community, there are similar and differentiating aspects in Turkish and Slavic mythologies. The beliefs about the moon are shaped by sacredness, respect and prophecy in the mythology of both communities. In this, the facts that the moon is close to the world changes the shape and size of the crescent to the full moon according to the rotation around the world, causes tide because of the gravitational force play a big role. In both mythological systems, the moon is associated with the sun. In this study, the meanings given to the moon in the mythic worlds of Turkish and Slavic communities will be mentioned, the facts related to the month will be mentioned and the reflections of the beliefs about the moon will be emphasized.