Global biodiesel production grew by 23% per annum between 2005 and 2015, leading to a seven-fold expansion of the sector in a single decade. Rapid development in the biodiesel sector corresponded to high crude oil prices, but since mid-2014, oil prices have fallen dramatically. This paper assesses the economic and policy factors that underpinned the expansion of biodiesel, and examines the near-term prospects for biodiesel growth under conditions of low fossil fuel prices. We show that the dramatic increase in biodiesel output would not have occurred without strong policy directives, subsidies, and trade policies designed to support agricultural interests, rural economic development, energy security, and climate targets. Given the important role of policy—and the political context within each country that shapes policy objectives, instruments, and priorities—case studies of major biodiesel producing countries are presented as a key element of our analysis. Although the narrative of biodiesel policies in most countries conveys win-win outcomes across multiple objectives, the case studies show that support of particular constituents, such as farm lobbies or energy interests, often dominates policy action and generates large social costs. Looking out to 2020, the paper highlights risks to the biodiesel industry associated with ongoing regulatory and market uncertainties.