Due to the globalization and interconnectedness of people from different cultures, intercultural competence is a prerequisite to communicating effectively across different cultures. The Intercultural Sensitivity Inventory (ICSI) measures a person's ability to modify behavior in culturally appropriate ways when coming into contact with diverse cultures. The ICSI is a measurement based on the concepts of individualism and collectivism. The majority of research on intercultural competence and intercultural sensitivity (ICS) has primarily focused on adult populations in business, international education exchange programs, and adult third culture kids (ATCKs). However, such research involving high school students attending an international school outside of the United States is scant.The purpose of this quantitative study was to examine the differences in intercultural sensitivity (ICS) among Third Culture Kids (TCKs). Specifically, this study assessed the differences in ICS among the independent variables of gender and participant's passport country. Additionally, the study examined the difference in ICS between Korean females and non-Korean females. The ICSI was used to measure the participants' ICS. The sample consists of 139 international high school students. The independent samples t-test revealed no statistically significant in ICS among males and females, as well as Korean females and non-Korean females. However, the results revealed a statistically significant difference between Korean and non-Korean students. Korean students scored lowered on the ICSI than their counterparts.