This article argues that the differences among subgroups of the Mexican diaspora are significant, as expressed through the variety of signifiers used to refer to various groups within this diaspora and affect intercultural communication and relations. The article first demonstrates that people of Mexican descent living within the current national borders of the United States can be considered a Mexican diaspora. It examines the lexicology and history behind five major signifiers—Mexican/ mexicano, Mexican American, Chicano/a, Hispanic, and Latino—used to refer to members of that diaspora and shows how they are the subjects of diasporic and postcolonial discourses. The article concludes with comments on three specific areas in which Mexican diasporic signifiers influence intercultural communication and affect communication research validity and provides suggestions for addressing these issues in future studies.