This study aimed to conceptually distinguish and clarify the term “domain,” which is used in various meanings in the social studies curriculum. To this end, the usage and meaning of “domain” in previous national curricula were analyzed, and the contents of the moral and Korean history curricula were reviewed as necessary, considering the relationship with the moral and Korean history curricula, which are separate subjects from social studies. Moreover, although the history curriculum has been developed separately from the social studies curriculum, the former is incorporated into the latter at the announcement stage. Thus, the contents of the history curriculum were also analyzed. The results showed that the meaning of domain in the social studies curriculum has been used interchangeably throughout the past curricula. However, when categorizing the meanings, domain is primarily used in three meanings: (1) the disciplines and their subfields on which the subject is based, (2) themes that run through the content system of elementary and middle school curricula, and (3) themes that bind the achievement standards. The results of this study have the following significance. First, the “domain” of the social studies curriculum, which is dealt with in a complex manner in the national curriculum and subsequent studies, was categorized and classified into three dimensions in order to clarify it. Second, this study contributed to reducing the administrative confusion between provincial and municipal offices of education and schools regarding the “domain” of the social studies curriculum while also raising the need for alternative terms. In the future, it is necessary to grant autonomy to set alternative terms for “domain” according to the characteristics of the underlying discipline or subject when revising the national curriculum, and this can also contribute to the subject’s uniqueness and the composition of a convergent content system based on it.