Global citizenship is a citizenship model that draws growing attention of practitioners and education theorists. Global identity is an important prerequisite for the development of global citizenship. This empirical study conducted in three social studies classrooms investigated whether social studies classroom discourse contributes to the emergence and development of students' global identities and what linguistic elements of discourse impact the development of students' global identities. Using the framework suggested by Bucholtz and Hall (2010), which analyzes identity as constituted in linguistic interaction, the study demonstrated how teacher mediated discourses are pertinent to the construction and development of global identity among students. By applying the indexicality principle, it was determined which linguistic symbols students identified as indexes of global identity. The study concluded that the use of words and phrases that relate indexically to global identity in the teacher's narrative or a textbook affects the development of students' global identities.