In this study, I analyze three significant mobilizations in Turkey\u27s pre-dominantly Kurdish-populated Southeastern region. These social movements, namely the Kurdish ethno-nationalist movement, the Gülen movement, and Hizbullah, claim to represent local Kurdish people by competing with one another for political influence, public recognition, and legitimacy. Despite the fact that social movement scholars have long discussed competition among social movement organizations (SMOs) within a movement, few studies have paid attention to inter-movement relations. The current literature on inter-movement relations is also unable to explain the dynamics of competition among divergent social movements. Some scholars focus on interactions between opposing movements (movement versus counter-movement), while others examine the spillover effects among similar movements who are friendly with one another. Dynamics of enmity and friendship, however, cannot sufficiently explain social relations when social movements perceive each other as rivals. This work contributes to the literature by introducing the concept of rival movements. Based on qualitative data including field interviews and analysis of social movement publications, I analyze the process of inter-movement competition. Three mechanisms are identified: resemblance, niche building, and strategic subversion. As the first comprehensive study on social movement rivalry, this study aims to fill the bridge between the ethnicity/nationalism literature and social movement theory.