ABSTRACT This study explores how both an external magnetic field and finite particle size influence the diffusion characteristics of two‐dimensional Yukawa systems. By employing the equilibrium molecular dynamics method, we calculate the mean‐squared displacements of particles and the diffusion coefficients across a broad range of system parameters. It is well established that magnetic fields reduce the diffusion coefficient by constraining particle motion within the system. Our research shows that the effect of finite particle size on diffusion is influenced by the degree of magnetization, resulting in either increased or decreased diffusion coefficients depending on magnetic field strength.