An emerging literature has begun to explore the acculturation of majority-group members within increasingly diverse societies, recognizing that this process does not occur within a social vacuum. Given the inherent power asymmetries and ethnic hierarchies that usually favor the majority group, it becomes critical to examine their acculturation process through the lens of power dynamics. Central to this examination is determining whether majority group’s adoption of other cultures constitutes cultural appropriation. In this paper, we theoretically delineate when majority-group acculturation equates to cultural appropriation and when it does not. We argue that cultural appropriation becomes evident when majority-group members exploit cultural elements from less powerful ethnic groups against their will, often for material gains, without providing proper credit or demonstrating a deeper understanding of the culture. By contrast, cultural adoption cannot be deemed appropriation when it manifests in deep rather than surface cultural learning, regards other cultural groups as equal and not inferior, and is accepted by the group whose culture is being adopted. Existing acculturation research suggests that the cultural adoption by majority-group members is typically driven more by egalitarian motives than by a desire for dominance, and that minority groups do not principally object to this adoption. Therefore, it is improbable that all aspects of majority-group members’ cultural adoption would constitute cultural appropriation. However, further research is needed to empirically differentiate cultural appropriation from genuine forms of cultural adoption within majority groups, particularly by investigating the perspectives of the groups whose cultures are being adopted.