In 2015, a global study estimating inputs of plastic waste into the oceans ranked Indonesia as the second largest contributor to plastic marine pollution. In 2017, another study ranked four Indonesian rivers in the world's most polluting top 20. The challenge of plastic waste and marine debris requires a robust national response to curb the significant impacts on Indonesian marine biodiversity, its communities and its economy. The Government of Indonesia (GoI) has signaled its leadership on combating plastic waste and marine debris - making strong commitments and setting ambitious targets to reduce plastic pollution and improve waste management. As the GoI implements this agenda, it is imperative we better understand the current state of this challenge. In this study, we provide the first Indonesia-wide assessment integrating local waste data with actual hydrological conditions to tell the story of how local practices contribute to marine plastic pollution.