The aim of the research is to assess the potential of agricultural biomass available in European Union countries that can be used for energy purposes. The research took into account the potential of agricultural biomass from: straw from cereal crops, hay from permanent grasslands, natural fertilizers from animal husbandry, cultivation of energy crops on fallow land and waste wood from permanent crops. The study estimated the theoretical potential presenting the energy value of all existing agricultural biomass resources in EU countries and the technical potential taking into account agricultural biomass resources that are not used in agriculture. The research was based on Eurostat data for 2019. The conducted research shows that European Union countries are characterized by a significant potential of agricultural biomass. However, due to the high demand for this resource in agriculture, about 15% of the existing potential can be used for energy purposes. Among the analyzed sources, the highest potential is characterized by straw from cereal crops and by the cultivation of energy crops on fallow land. The conducted research also indicates a large spatial differentiation of the potential of agricultural biomass in European Union countries, which may have a negative impact on the economic efficiency of using this renewable energy source.