Herein, SmFeO 3 thin films are prepared by using magnetron sputtering technology on quartz-glass and SrTiO 3 (STO)(1 0 0) substrates. The influence of film thickness and choice of substrate on film quality and growth orientation is studied in detail. Moreover, the impact of phase purity and growth orientation on optical, magnetic and magneto-optical properties is discussed. The results reveal that the film thickness and choice of substrate significantly influence the induced stresses at film/substrate interface and growth orientation of the annealed film. The as-fabricated SmFeO 3 thin films have demonstrated highly crystalline structure, excellent transmittance and enhanced magneto-optical properties. Moreover, obvious anisotropy in magnetization and magneto-optical properties has been observed. The SmFeO 3 films with excellent magneto-optical properties can be fabricated by selecting optimal film thickness and substrate. It is expected that SmFeO 3 film is a promising material for integrated optical isolators and magneto-optical modulators.