In this study, combustion kinetics of swine manure as well as algae grown using swine manure wastewater were investigated. Four heating rates (1, 5, 10, and 20 K min−1) were used to determine combustion kinetics using thermogravimetry. Swine manure solids showed higher carbon concentration (10.6 %) and hydrogen concentration (18.8 %) as well as energy content (14.2 %) than algal biomass solids. Each feedstock showed a distinct decomposition profile that increasingly shifted with increasing the heating rate. The combustion kinetics parameters were determined using Kissinger, Flynn–Wall–Ozawa (FWO), and Kissinger–Akahira–Sunose (KAS) methods. Differences in activation energy values between FWO and KAS were below 2 % throughout the entire conversion. Average activation energy for swine manure and algae, using FWO, was 172.6 and 165.1 kJ mol−1, respectively. Combustion of three blends of algae–swine manure solids was studied at 10 K min−1 with no synergistic effects observed.