Fiscal spending policies adopted in the wake of the COVID-19 pandemic have been presented as a unique opportunity to “build back better” and re-ignite the economy while accelerating the transition to a low-carbon economy. This paper analyses 1 166 funding measures announced by 51 countries and the European Union in 2020-21 to support development and diffusion of low-carbon technologies. These measures – amounting to USD 1.29 trillion – can make an important contribution to filling the climate investment gap, particularly in emerging technologies such as carbon capture, usage and storage and green hydrogen. A modelling analysis suggests that they could have large impacts on greenhouse gas emissions and bring about significant co-benefits in terms of clean sectors’ output growth and reductions in fossil fuel imports.