<p>Nanofluids play a crucial role in modern technology by significantly improving thermal management systems, leading to more efficient and compact designs. Their enhanced heat transfer capabilities are pivotal in advancing fields like electronics cooling, renewable energy, and medical treatments. Acknowledging this diverse significance, a numerical study was carried out to investigate the mass and heat transfer properties of Casson nanofluid flowing past an exponentially stretching surface. This research systematically examined Brownian motion’s impact, thermal radiation, gyrotactic microorganisms, and thermophoresis in two key scenarios: Newtonian fluid motion and non-Newtonian fluid motion. A streamline function is also used to see the behavior of velocity. Initially, the governing physical equations are described by a series of nonlinear PDEs. This system was transformed into a set of ordinary differential equations by using the appropriate transformations, which allowed for a complete analysis. By utilizing the computational capabilities of the Runge–Kutta technique, these equations were effectively solved. The multilinear regression approach was utilized to simulate the solutions of flow parameters. The outcome of this effort unveiled visual representations illustrating the complexities of both Newtonian and non-Newtonian fluid dynamics. These visual depictions, accompanied by elaborate tables, offered insights into various physical characteristics of the system. Of particular interest were the detailed descriptions of thermal and diffusion profiles, in addition to the rates of heat and mass transfer. The enthralling field of bio-convection has attracted considerable attention because of its extensive applications in areas such as healthcare, cancer therapy, contemporary defense technology, advanced aviation production, enhanced electronic devices, efficient energy storage, water purification, and beauty product development.</p>