Chapter to appear in: Williams, Jerome D., Wei-Na Lee, and Curtis P. Haugtvedt, eds. (forthcoming), Diversity in Advertising, Hillsdale, NJ: Lawrence Erlbaum Associates, Inc., This chapter discusses the significance of distinctiveness theory for understanding advertising persuasion in multicultural marketplaces. First, we define distinctiveness theory, reviewing the initial empirical tests that formed the distinctiveness postulate and describing its underlying psychological assumptions. We also discuss other research that extends various elements of distinctiveness theory and attests to its robustness. Then, we review consumer applications of distinctiveness theory, and link this discussion to our understanding of the psychological processes affecting advertising responses. Our goal is to demonstrate how powerful the distinctiveness construct is in understanding advertising persuasion among multicultural audiences. Finally, we suggest directions for future research that capitalize on and extend the distinctiveness construct.