In this study, bimetallic (Cu–Mn) substituted SrFe12O19 hexaferrites [Sr1−2xMnxCuxFe12O19 (0.0 ≤ x ≤ 0.1)] were synthesized via sol–gel auto-combustion approach. The effect of bimetallic substitution on structure, morphology and magnetism of SrFe12O19 was investigated. SEM images divulge the nano-size of the prepared products with speck morphology. X-ray powder diffraction analysis affirmed their complete conversion to SrFe12O19 hexagonal crystal phase. The results from 57Fe Mossbauer suggested that all five important sextets of Sr1−2xMnxCuxFe12O19 hexaferrites effected due to the substitution of Cu and Mn ions. Cation distribution calculation showed that as the percentage of Mn and Cu increased in Sr1−2xMnxCuxFe12O19 (0.0 ≤ x ≤ 0.1), particularly for x = 0.03 the relative area of 12k and 4f2 site increased. This indicates that Fe ions are migrated towards 12k and 4f2 octahedral site.