This thesis is the first ethnographic attempt to study contemporary dissident activism in Vietnam. As a country that became known and keeps being remembered as a war-torn postcolony by the West, Vietnam has managed to lift itself from one of the poorest to one of the fastest growing market economies in Southeast Asia. Yet, while holding on to the legacy of a communist-led liberation movement, the present-day Communist-Party (CPV) itself became subject to political challenges from below. In fact, dissident voices critical of the government's malgovernance over social, economic and environmental issues have mushroomed across regions, classes and generations. Based on 52 interviews with activists and numerous informal conversations with citizens conducted over a period of 11 months across Vietnam, this thesis interrogates distinct political practices and political ideas of Vietnamese dissidents. In doing so, it explores different anti-capitalist and anti-authoritarian practices including online activism for democratic change (Chapter 7), rights-based resistance of workers and peasants (Chapter 8) and religious politics against environmental and social injustices (Chapter 9). What these practices have in common is the disclosure of politically subjugated knowledges (see Foucault 1976). On the way to exploring these subjugated knowledges, this research has revealed how anti-capitalist and anti-authoritarian practices of Vietnamese activists are motivated by a set of contradictory political ideas and concepts including nationalism, anti-communism, statism, legal ideology, liberal democracy and Catholicism displaying the continuous hegemony of Westerncentric epistemologies in non-Western societies. Understanding this dissonance between political practices and political ideas lies at the heart of this study. By drawing on a decolonial-Marxist theoretical framework, I situate this dissonance between practices and ideas within the system of capitalist totality, ideological state apparatuses and epistemological coloniality. This thesis suggests a distinction between resistance in itself and resistance for itself. I conceptualise that resistance in itself is concerned with political practices that are mostly reactive to immediate moments of state repression (state-society relations), while resistance for itself centres on actively trespassing on the spatiality of ideological systems and ideological state apparatuses via capitalism, coloniality, nationalism and state institutions such as the judiciary (capital-epistemology relations). Thus, the trespassing on ideological systems and apparatuses hinges on a process I call cognitive resistance by which activists re-contest political concepts from dominant ideologies and re-insert them into new ideational structures. In other words, cognitive resistance gives new meaning to political concepts. Overall, this thesis argues against the idealization of resistance in Southern social movements but, instead, calls for a better understanding of the embeddedness of social movements within local and global structures shaped by capitalism, state authoritarianism and epistemological coloniality alike.