The purpose of this study is to review the previous studies in the integration of international faculty at Japanese universities. This paper begins with illustrating the research background, research purpose, and research focuses or questions. The paper then reviews previous studies relating to the integration of foreigners and international faculty based on migration theories. The main points include that the terminology of integration is originally from English, however, there exists no clear concept in this regard. In addition, the interpretation of integration varies considerably depending on the fields of scholars and professionals. The third part of this paper focuses on reviewing prior literature of international faculty at Japanese universities. Although a number of previous studies in the demographic characteristics, professional roles, and perceptions of international faculty have been conducted, the attention paid to the integration of international faculty is extremely limited. Based on the literature review above, the paper identifies major issues concerning the existing research and presents the author’s definition of the integration of international faculty at Japanese universities.