Agricultural and forest residues could become potential sources of energy in various countries. However, incomplete understanding regarding physico‐chemical properties of these residues presents the main challenges for energy conversion processes. This study presented a complete and comprehensive database of characteristics and compositions of a wide range of agricultural and forest residues. Physical characteristics (moisture, bulk density, calorific value, volatile matter, fixed‐carbon content, and ash content), elemental compositions (C, H, N, O, and S), as well as lignocellulosic compositions (cellulose, hemicellulose, and lignin) of ten biomass residues were analyzed. The major impacts of the variability in biomass compositions to biochemical and thermochemical processes were also discussed.