Native polyculture microalgae have significant potential as feedstocks for biofuels, but a thorough understanding of their pyrolysis kinetic parameters is required to convert them to biofuels efficiently. This study used thermogravimetric analysis (TGA) to examine the pyrolysis properties and kinetics of native polyculture microalgae. The biomass was pyrolysed from room temperature to 800 °C at four heating rates: 10, 20, 30, and 40 °C min−1. The thermal decomposition was analysed using two model-free methods: Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO). It was found that thermal decomposition occurred in three stages: the dehydration stage, the active pyrolysis stage, and the passive pyrolysis stage. The maximum decomposition occurred between 186.7 to 531.7 °C, indicating the simultaneous decomposition of carbohydrates and proteins. The higher heating rates increased the total volatile matter and moved the peak pyrolysis temperature to a higher value due to limited heat transfer. The average activation energy determined by the KAS method (144.11 kJ mol−1) and the FWO method (147.43 kJ mol−1) were in agreement with each other, indicating that the obtained results are reliable. Also, a high R2 of 0.96 – 0.99 indicates that the points fit well. These findings provide useful information for designing pyrolytic systems using polyculture microalgal feedstock and suggest that polyculture microalgae could be a cost-effective alternative for biofuel production.