For the first time, sustainable LaFeO₃ powders were prepared from soluble bio-based substances (SBO) extracted from urban wastes. For the preparation of the perovskite-type powders, a modified solution combustion synthesis route was used, where SBO have the triple role of fuel, complexant and microstructural templates. A careful examination of the LaFeO₃ powders, using complementary characterization techniques, evidenced their peculiar microstructural, morphological, textural and photocatalytic properties. Preliminary photodegradation tests of a phenol-based wastewater pollutant and photobleaching of a model dye were performed on the waste-derived and reference LaFeO₃ powders; the obtained results encourage further studies on the application of these materials as heterogeneous catalysts for wastewater treatment. Moreover, a meaningful amount of entrapped matter was evidenced in the powders, which is responsible for most of their peculiar properties.