Reactive Black 5 is widely used in the textile industry for dyeing cellulose fibers such as cotton, rayon, and linen. It provides deep black shades with good color fastness to washing and light exposure. The dye forms a covalent bond with the fiber during the dyeing process, which enhances durability and reduces bleeding. It is commonly applied in batch dyeing processes under alkaline conditions using reactive dyeing methods.

In addition to textiles, Reactive Black 5 is used in paper printing and leather dyeing where strong, dark colors are required. It is also employed in some industrial applications for coloring cellulose-based materials. However, due to its complex aromatic structure and potential environmental persistence, treatment of wastewater containing this dye is a critical concern in industrial settings.