This article explores how international-mindedness is defined and cultivated in the International Baccalaureate (IB) Middle Years Program (MYP) schools in different regions of the world as young adolescents face their main developmental task of identity development. An online survey that contained demographic and open-ended questions was administered to MYP students. Mixed methods design and data analysis provided insight into the ways international-mindedness is experienced and developed within the IB community. Open-ended responses were analyzed using thematic analysis from which a grounded theory emerged. The most frequently mentioned themes in defining international-mindedness were understanding, awareness, and acceptance of different others. Respondents emphasized that family and school experiences were the main factors that influenced their international-mindedness with travel being frequently mentioned in both. Factors, such as make-up of participants' families, their history of moving internationally, and the advice and modeling provided by parents and extended family as well as school experiences (e.g., field trips, debates, multicultural classrooms, curriculum focus) significantly contributed to their high self-ranked stance on the developmental continuum of international-mindedness. Consistency in responses across the regions demonstrate a paradigmatic understanding of international-mindedness among the respondents.