The concept and definition of Islamic civilization is one of the topics that has been the subject of debate among scholars, and various definitions have been proposed . Among them, there are several main views : The first view, based on the criteria of Islam, defines an Islamic civilization as one that emerged from the religion of Islam and its teachings . The second view, based on the criteria of Muslims, considers Islamic civilization to be the same civilization that Muslims created in historical reality. has been achieved . The third view, with the criterion of the Islamic world, is of the opinion that Islamic civilization is a civilization that has been formed in the geography of the Islamic world. The present article, using a descriptive, analytical method and through the examination and criticism of the above views, seeks to answer the question of what is the main criterion for defining Islamic civilization? The author claims that the main criterion for defining Islam is "Islam" and the other two criteria, namely Muslims and the Islamic world, are subordinate to it and dependent on it; because although Muslims are the creators of Islamic civilization and this civilization has been formed in the geography of the Islamic world , Muslims and the Islamic world are also defined by the validity of Islam and do not have an independent identity apart from Islam . What has originality and independence is Islam, and Islamic civilization is also called Islamic by its validity.