The aim of the present work is to investigate the influence of Samarium ions doping in the TiO2 host lattice and the contribution to the optical properties of this semiconductor. The X-ray diffraction pattern shows the formation of anatase phase TiO2 nanoparticles of average sizes 7.8 nm, 7.21 nm and 6.1 nm for both pure and 1 wt% and 4 wt% of Sm3+ doped samples respectivity. Energy Dispersive X-ray (EDX) spectroscopy confirms the presence of Sm ions within the Sm substituted TiO2 nanoparticles. These results suggest that, Pure and doped TiO2 samples confirm anatase phase of good crystallinity with smaller crystallite size. UV–visible spectra display stronger absorption in the visible region. The photocatalytic experiments are investigated by the removal of rhodamine B under UV light. Compared to the other two photocatalysts, the results shows that 4 wt% of Sm3+ doped TiO2 exposes the highest photocatalytic performance.