Ancient Egyptian symbols were employed to represent a wide range of concepts and ideas during different periods of the Egyptian civilization like the idea of trinity. Trinity was formed by combining three components. This idea came into existence from the Pre-dynastic period till the Christian era. Moreover, the ancient Egyptians worshipped their deities in groupings known as triads. Triads are classified into two types: regular and irregular. Furthermore, three used to appear as guardian demons in the Ancient Egyptian religious books. Moreover, in the ancient Egyptian mythology, three signify conflict. Additionally, the ancient Egyptians communicated with the deceased in three different ways. Also number three has an importance in the sacred architecture in ancient Egypt. This study aims to demonstrate the significance of number three and the earliest appearance of numerals in Ancient Egypt. Furthermore, the origin of the idea of trinity. Later, this idea developed into the triad. The methodology of this paper is to study number three and the idea of trinity from the ancient Egyptian religious aspect. However, while seeking to comprehend the ancient Egyptians, their culture, and their symbols one should first understand and study their religion, as the ancient Egyptian religion affects them in all the aspects of their life.