Fossil fuels produce harmful gases that adversely affect the environment and human health. Although some sources of energy (e.g., solar, wind, and biofuels) are clean and renewable, substantial research is required to compete with fossil fuels. Several research studies are available on parabolic trough solar collectors, but process modeling and the influence of input parameters on optimization to enhance efficiency are hardly tried. The present study involves modeling and optimization of the efficiency of novel parabolic trough solar collectors under laminar flow conditions using magnetic nanofluids (NF). The study is conducted in two steps; the first step involves developing a predictive model using Response Surface Methodology (RSM). The second step consists of calculating the optimum parameters for maximum parabolic trough solar collector efficiency. NF weight %, temperature, and magnetic flux were selected as input parameters. The developed model was further tested and validated using experimental results, and the agreement is promising with R2 0.966. Two optimization case studies were explored, focusing on the efficiency maximization of parabolic trough solar collectors. In the first case study, the constraint was set to minimize the NF wt.% while in the second case study, all the inputs were unconstrained. In the first case study, the efficiency was 61.69%, with a desirability of 0.71. In the second case study, the efficiency was increased up to 80.44% with the desirability of 1. The increase in the efficiency of the second case study is mainly due to the NF wt.% increased from 0.188 to 0.7388.