his study comprehensively examines the effects of particle size and temperature on the magnetic properties of iron oxide nanoparticles. These nanoparticles are highly sought after due to their exceptional properties, which make them suitable for a wide range of applications, including medicine, electronics, and environmental remediation technologies. In this research, the paramagnetic behavior of iron oxide nanoparticles is analyzed using the Langevin model under varying particle sizes and temperature conditions. Numerical simulations indicate that an increase in temperature reduces the saturation magnetization of the nanoparticles. This behavior is attributed to the enhanced thermal fluctuations of the spins, which disrupt magnetic alignment. Conversely, larger particle sizes result in higher saturation magnetization, a phenomenon primarily linked to diminished surface effects and stronger exchange interactions among the spins. These findings provide fundamental insights into the relationship between structural and thermal parameters and the magnetic properties of iron oxide nanoparticles, offering valuable guidelines for their optimization in cutting-edge technologies, including biomedical devices, magnetic storage systems, and environmental solutions.