Research in cancer therapies is rapidly advancing and demands the exploration of innovative approaches to further improve the efficacy of treatment. Here a multimodal approach for cancer therapy is reported which combines bioactive targeting, magnetic hyperthermia, and controlled drug release. For this, a nanoformulation MNP‐Chi‐Dox‐Ab, is bioengineered by conjugating CA 15‐3 antibodies to doxorubicin‐loaded functionalized magnetic nanoparticles (MNPs). Solvothermally synthesized MNPs of uniform spherical shape and size are functionalized with thermo‐pH‐responsive chitosan. The nanoformulation showed higher drug release of ≈65% at pH 5 and 42 °C temperature compared to the release at physiological pH and temperature. Furthermore, in an alternating magnetic field drug release is enhanced to 74%. Cytotoxicity studies in MCF‐7 breast cancer cells confirm the active targeting potential of the nanoformulation. For the nanoformulation without bioactive molecule (anti‐CA 15‐3) only 18% cancer cell death is noted whereas with the conjugation of anti‐CA 15‐3, 43% cell death is recorded. Flow cytometry studies revealed an increased apoptotic population at hyperthermic temperature (42 °C) compared to the physiological temperature. These results suggest that MNP‐Chi‐Dox‐Ab nanoformulation represents a promising multimodal platform for synergistic breast cancer therapy by combining active targeting, controlled drug release, and hyperthermia.