This study examines which factors influence support for reducing fossil fuel subsidies and what types of information shift people's views through surveying 37,000 respondents across 12 middle-income countries that provided over US50 billion in explicit and implicit subsidies for fossil fuels in 2022. Respondents were randomly allocated to receive information about the relative cost of fossil fuel subsidies, how they are regressive, or worsen climate change and air pollution. They were then asked about their support for reforms with and without accompanying policies. These treatments, particularly about environmental damage, increased support for reforms in countries that primarily subsidize gasoline and among respondents who perceive themselves to be middle class. Around 30 percent of respondents supported reducing fossil fuel subsidies in isolation, but this share increased to over 95 percent if accompanying policies were implemented. These findings help inform governments about how to build public support for phasing out fossil fuel subsidies.