Migration is a common phenomenon in the present lifestyle, where people move for jobs or education and other reasons from one country to another. This kind of migration is more evident among the millennial population. The purpose of this study is to understand the food adoption behavior of migrant millennials by proposing a theory using a grounded theory approach. Qualitative methodologies in the form of the grounded theory approach were applied since the purpose of the study was to generate a contemporary theory to better understand the food adoption perspective of migrant millennials. The participants underwent focus group discussions and the sample size was considered based on theoretical saturation. Transcriptions of focus group discussions were subjected to open coding, axial coding, and selective coding in order to unfold the concepts grounded in the data. The concepts were then integrated into a theory of food adoption behavior by writing a summary memo. The findings of the study indicate that the food adoption behavior of millennials is related to three constructs namely consumption habits, food attributes, and service attributes. The consumption habits represent millennial motivation, socialization, and food neophilia. The food attributes represent variety, popularity, hygiene, and taste. The service attributes are related in the context of quick service. The proposed theory will enable marketers and food services outlets to understand the food adoption behavior of migrant millennials and customize their offerings to the specific needs of the customers. A contemporary theory on migrant millennials’ food adoption behavior has been proposed which overcomes the limitations of existing theories.