Due to sustainable and green processing requirements from buyers, the researchers are working on natural dyes to dye textile materials. In this study, cotton fabric was successfully dyed with a natural colorant which was extracted from black tea, and aloe vera was used as a natural mordant to enhance the fixation of natural dyes. The aqueous extraction method was used to extract colorant from black tea powder in a water bath at the temperature of 85–95 °C for 60 min. Three mordanting techniques were applied for cotton dyeing by changing parameters such as dye concentration (2, 4, 8 % o.w.f) and mordant concentration (20, 40, and 60 g/L). Pretreated cotton fabric was dyed on a high-temperature (HT) dyeing machine at 80 °C for 40 min at pH 5.5. The dyed cotton samples were analyzed for color strength (K/S), colorfastness, and antibacterial assessment (qualitative) using standard test protocols. The results showed that the maximum color strength value was achieved with 8 % dye and 60 g/L mordant using pre mordanting method. The dyed fabrics revealed excellent colorfastness to washing, whereas the color fastness to light, perspiration, and crocking was satisfactory. The antibacterial property of the dyed fabric was also satisfactory which is confirmed by no colonial growth on or below the samples. In a nutshell, this study presented an ecofriendly approach using black tea leaves and aloe vera contributing to green and sustainable production.