Spent coffee grounds (SCG) are rich in valuable nutrients, including dietary fiber, proteins, lipids, vitamins, minerals, and various bioactive compounds. In the context of food science, it is essential to reconsider SCG not as waste, but as a potential functional ingredient that can be valorized to reduce environmental impact and enhance nutritional and economic value in food systems. In this study, SCG of Turkish, espresso, or filter coffee was evaluated as a resource of dietary fiber and antioxidants in beef patties during refrigerated storage over 7 days. Physicochemical (pH, water activity, color, cooking loss, diameter reduction, dietary fiber content, and oxidative stability), textural, and sensory traits of beef patties were determined. The spent coffee ground treatment significantly increased the dietary fiber content of the samples (p < 0.05). The lowest TBARS number was found in the groups of treatment (T1, T2, and T3) on the 7th day. Additionally, the pharmacokinetic properties and safety profiles of selected SCG-derived phytochemicals were assessed using ADMET analysis, revealing favorable bioavailability and non-inhibitory effects on cytochrome P450 enzymes. Molecular docking studies against the 2FLU (Kelch-Neh2 Complex) target protein demonstrated strong binding interactions, with chlorogenic acid exhibiting the highest affinity (−9.3 kcal/mol, Ki: 0.152 μM). The sensory scores showed that incorporating SCG, especially Turkish and filter coffee grounds, improved the odor properties of beef patties but adversely affected texture due to their fibrous and porous nature. Yet, general consumer acceptability was higher for these samples compared to the control group. As a result, utilizing SCG as a resource of antioxidants and dietary fiber in meat products represents a viable, natural, and cost-effective solution for the meat industry.