We report an intriguing twofold spin reorientation transition of type 4 (G x ,A y ,F z ) → 1 (A x ,G y ,C z ) → 2 (F x ,C y ,G z ) for the Fe 3+ magnetic sublattice near spin reorientation temperatures T SR1 ß 77 K and T SR2 ß 45 K in a rare-earth orthoferrite Dy 0.5 Pr 0.5 FeO 3 single crystal. Magnetic-field-induced incomplete spin-configuration transitions ( 4 → 41 → 42 for H = 20 kOe and 4 → 42 for H = 40 kOe) were observed by measurement of magnetization as a function of temperature. The spin reorientation temperature of a Dy 0.5 Pr 0.5 FeO 3 single crystal can be controlled by changing the magnitude of the applied magnetic field. We also show that spin reorientation of the 1 → 4 type between T SR2 and T SR1 can be induced by an applied magnetic field along the c axis. The origin of the intriguing magnetic behavior is ascribed to the anisotropic effective field whose strength is determined by the interactions with R 3+ (R = Dy, Pr) spins and can be modified by the external applied magnetic field. It provides deeper insight into the Fe 3+ -R 3+ magnetic interaction which dominates the sophisticated magnetic phase transitions in the rare-earth orthoferrites.