Broader contextHeterogeneous catalysis possesses immense potential to transform lignocellulosic biomass into liquid fuels and chemicals. This article reviews the existing routes in biomass conversion that use heterogeneous catalysts and discusses the role of catalytic science. Over the last 20 years new cutting-edge experimental, synthetic and theoretical techniques have been developed that can now be applied to the conversion of biomass into fuels and chemicals. These cross-cutting tools will allow us to rapidly develop new catalysts and catalytic processes for the conversion of biomass into fuels and chemicals.