Production of chemicals and fuels from renewable biomass is a hot topic of current research. Theoretically, most of the fuels and chemicals from petroleum resources can be synthesised from biomass. Oxidation is one of the most important methods in chemistry for biomass upgrading. H2O2 is a green and liquid alternative of gaseous oxygen. The incorporation of existing and the state-of-the-art chemistry associated with H2O2 creates new strategies for biomass valorisation. In this review paper, we summarize the application of H2O2 as an oxidant for biomass conversion to chemicals over the last decade, especially those processes with high industrial interest. We will focus on four topics: (1) lignin depolymerisation, (2) selective oxidation of carbohydrates, (3) oxidation of furan compounds (HMF, furfural) to carboxylic acids, and (4) C[double bond, length as m-dash]C double bond cleavage for unsaturated fatty acids. We attempt to map the major achievements in these areas, identify the methodological problems, and highlight the outstanding research questions and gaps. We hope that this paper will provide the readers with information based on the existing knowledge and better insight into the future development of such technologies.