National unity is considered one of the pillars of the nation’s components and the foundations of its development and progress. It is also almost the basis for its stability and growth, as sound national construction is based on it and constitutes the goal and first goal of political development. Therefore, it is necessary to shed light on this important aspect of the nation’s entity, especially since Islam has paid great attention to it because of its effects on people in general. Therefore, this was a simplified study, which included several axes, namely unity in the Islamic concept and achieving it during the Hajj season. It also touched on the Prophet’s migration and the achievement of Islamic unity in Medina. It also addressed the effects of the Prophet’s migration, represented by brotherhood and the delegations of Arab tribes to Medina.The study also dealt with the morals of the Prophet, may God bless him and his family, and his tolerance in achieving unity in Medina, as well as at the conquest of Mecca, and his method, peace and blessings be upon him, in preserving that unity throughout his life. The study briefly dealt with the role of hypocrites in their effort to weaken unity and destroy it.