The Stokes-Mueller calculus and θ-scan technology were used to investigate optical effects in liquid crystals doped with γ-Fe2O3 nanoparticles. The results showed that the dichroism decreased monotonously with increasing nanoparticle concentration, while the ellipticity decreased when the nanoparticle concentration increased from 0 to 0.06 wt%, but increased when the nanoparticle concentration increased from 0.06 wt% to 0.1 wt%. The apparent phase delay can be used to distinguish between different values of Nπ, revealing the intrinsic birefringence of the liquid crystal. The intrinsic birefringence decreases monotonically with increasing nanoparticle concentration. These results suggest that the optical properties of liquid crystals can be significantly modified by doping with nanoparticles. The findings of this study have important implications for the development of new liquid crystal display devices.