Abstract This work presents the synthesis and characterization of hard/soft (1-x)SrFe₁₂O₁₉/xCoFe₂O₄ exchange-coupled nanocomposites with x = 0.0, 0.05, 0.1, and 0.2 using the conventional coprecipitation and ball milling preparation methods followed by heat treatment. CoFe₂O₄ material was used as a soft magnetic material when the effects of its concentration on the structural and magnetic properties of the obtained nanocomposites were investigated using different characterization techniques. Structural and microstructural analyses showed the presence of both spinel ferrite and the M-type hexaferrite phase. Single-phase magnetic loops were observed for the prepared nanocomposites, indicating an exchange coupling interaction between CoFe₂O₄ and SrFe₁₂O₁₉ phases. To support this finding, a Henkel plot was performed, which revealed the presence of strong exchange coupling interaction in CS5 compared to CS10, unlike CS20, where the dipolar interaction is dominant. The obtained results demonstrate the possibility of enhancing the (BH)_max of the M-type strontium hexaferrite through an exchange-coupled nanocomposite, using a simple and reproducible synthesis process with a small content of the soft magnetic phase.