Presently, appropriate waste management is one of the main requisites for sustainable development; this task is tackled by the material construction industry. The work described herein is focused on the valorization of granite waste through incorporation, as a filler-functional admixture, into cement-based mortar formulations. The main components of the waste are SiO2 (62.1 %), Al2O3 (13.2 %), Fe2O3 (10.1 %), and CaO (4.6 %). The presence of iron oxides is used to develop the photocatalytic properties of the waste. Following heating at 700 °C, α-Fe2O3 forms in the waste. The inclusion of the heated sample as a filler admixture in a cement-based mortar is possible. Moreover, this sample exhibits a moderate ability in the photodegradation of organic dye solutions. Also, the plastering mortars, in which the heated samples have been used, show self-cleaning properties. The preparation of sustainable building materials is demonstrated through the adequate reuse of the granite waste.