COVID-19 has been a growing global concern in the past four years. Several syndromes associated with this multi-organ viral infection have been observed since the outbreak. According to estimates, 10–15% of people with SARS-CoV- infection may have post-COVID-19 syndrome. Even months after infection, common residual signs and symptoms include myalgia, exhaustion, shortness of breath, rapid heartbeat, stroke, and memory and cognitive impairment which can negatively affect survivors’ quality of life and may consequently lead to their death. Therefore, it is necessary to think about potential therapy options for dealing with both short and long-term impacts. Paracetamol (a common analgesic and antipyretic) and Dexketoprofen Trometamol (a non-steroidal anti-inflammatory drug) are used together to relieve post-COVID symptoms like myalgia (muscle pain) and headache. Additionally, to prevent thrombotic events, Rivaroxaban is recommended for 35 days following discharge. Thus an eco-friendly HPLC-DAD technique was developed for simultaneous quantification of Paracetamol, Dexketoprofen Trometamol, and Rivaroxaban which are co-administered for treatment of post-COVID-19 syndrome. The suggested method was found to be linear in the concentration ranges of 3.00–45.00 µg/mL, 0.5–50.00 µg/mL, and 0.15–20.00 µg/mL, and a limit of detection down to 0.531 µg/mL, 0.095 µg/mL and 0.047 µg/mL for Paracetamol, Dexketoprofen Trometamol and Rivaroxaban, respectively. This method was effectively used to quantify the studied drugs in their bulk powder and spiked human plasma with high percentage recoveries (96.55–99.46%). The suggested approach was validated per International Conference on Harmonization (ICH) requirements and found to be within the acceptable ranges. The method was developed using Green Analytical Chemistry (GAC) principles, with the solvents used and run time having a significant effect on the method’s greenness. “Non-toxic” ethanol served as the organic modifier in the mobile phase, moreover, the total run time was 12 min making it suitable for the routine analysis of the mentioned drugs in plasma samples. To get a full image of the method’s greenness profile; two most recent greenness assessment tools, the Green Analytical Procedure Index (GAPI), and the Analytical GREEnness metric (AGREE), were employed, with White Analytical Chemistry (WAC) principles proving its environmental safety.