The current examination used a multi-criteria decision-making (MCDM) approach to optimize the roughness parameters of S shaped ribs (SSRs) in a solar thermal collector (STC) duct using air as the working fluid. Different SSRs were tested to identify the combination of parameters resulting in the best performance. Geometrical parameters such as relative roughness pitch (PR/eRH) varied from 4 to 12, relative roughness height (eRH/Dhd) from 0.022 to 0.054, arc angle (αArc) from 30◦ to 75◦, and relative roughness width (WDuct/wRS) from 1 to 4. The Nusselt number (NuRP) and friction factor (fRP), findings which impact the STC performance, rely on SSRs. The performance measurements show that no combination of SSR parameters lead to the best enhancement heat transfer rate at low enhancement in the friction. So, a hybrid multi-criteria decision-making strategy using the Analytical Hierarchy Process (AHP) for criterion significance and Multi Attributive Border Approximation Area Comparison (MABAC) for alternative ranking was used to determine which combination of geometrical parameters will result in the optimum performance of a roughened STC. This work employs a hybrid MCDM technique to optimise the effectiveness of an STC roughened with SSRs. To optimize the SSR design parameters, this study used the hybrid AHP-MABAC technique for analytical assessment of a roughened STC. The optimization results showed that the STC roughened with SSRs achieved the optimum performance at PR/eRH = 8, eRH/Dhd = 0.043, αArc = 60◦ and WDuct/wRS = 3.