Eu3+-doped BiOCl with different doping concentrations was synthesized by a simple combustion method. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and UV-vis diffuse reflectance spectroscopy. The experimental results show that Eu3+ was successfully doped into the lattice of BiOCl. The as-synthesized Eu3+-doped BiOCl photocatalysts show a more intense continuous absorption in UV light region, accompanied with decreased energy band gap. Moreover, the Eu3+ doping leads to the formation of oxygen vacancies, small crystallite size, and high specific surface areas. Compared with pure BiOCl, the Eu3+-doped BiOCl photocatalysts exhibits much higher photocatalytic activity for Rhodamine B (RhB) under UV light irradiation. As-obtained Eu3+-doped BiOCl can be easily reused with excellent stability. In addition, the mechanism of the improved photocatalytic properties of Eu3+-doped BiOCl was discussed in detail.