Subsidies can directly support unsustainable fishing practices that harm both ecosystems and long-term social and economic benefits. Globally, fishery subsidies total around US$27 billion, yet their impacts on fishing dynamics are specific to given regions or particular fisheries and fishery subsidies within a nation have markedly different effects when applied to artisanal versus industrial, or managed versus open-access conditions. A range of subsidy reform strategies are critically assessed, drawing on a review of over 30 case studies worldwide to determine patterns in their usefulness and necessary conditions for implementation. Strategies with best overall results are explicitly reorienting subsidies away from capacity-enhancement, and/or conditioning them on specific sustainability performance metrics. Decoupling subsidies from fishing (e.g. providing direct aid to fishers) has unpredictable and unclear results, whereas buyback programs have mostly, and sometimes significantly, poor outcomes. Eliminating subsidies is perhaps the simplest strategy, but is also the most difficult to implement from a social and political perspective. There are clear patterns in effective and beneficial subsidy reform strategies, though key factors for any policy to succeed are clear short- and long-term goals; creative design; transparent implementation; and strong socio-political will.