This chapter provides an overview of the literature on the voice opportunities for digital platform workers. Worker voice - how workers can have a say in organizational affairs - tends to be limited in the platform context because gig- or crowdworkers typically lack employment status. Yet, the literature points to several avenues for increasing platform worker voice, ranging from initiatives driven by workers directly, to unions, regulators, and, sometimes even platforms themselves. Distinguishing voice on the formal-informal, individual-collective continuums when sorting the literature, we identify various hot spots and blind spots in extant research and derive four policy implications. First, workers need to be able to network and organize. Second, unions need to be able to access platform workers directly. Third, unions must develop sustainable digital unionizing strategies. Fourth, policymakers need to consider voice when designing platform regulations. Our chapter contributes to a better understanding of the relevance of voice in digital work contexts and debates about labor conditions in the platform economy and the societal impact of platforms more broadly.