Background Breast cancer is the most common cancer amongst women in both the developed and less developed world. It impacts over 1.5 million women worldwide each year. Doxorubicin (DOX) is a widely used drug for breast cancer. However, researchers are still looking for appropriate delivery system that can overcome acquired resistance and toxicity associated with DOX. Casein nanomicelles, the major fraction of milk protein, are emerging as a novel drug delivery system owing to their various structural and functional properties. Methods DOX was successfully loaded into sodium caseinate nanomicelles (NaCNs) which were formulated and optimised through magnetic stirring. Zeta size and zeta potential of formulations were measured and then formulations were further characterised through FESEM, TEM, FTIR and XRD. In-vitro drug release study was also assessed by using dialysis membrane. Results NaCNs yielded sizes that ranged from 348.8 nm (blank micelles) to 604 nm (drug-loaded micelles) and, negative zeta potential of -22.1 (blank micelles) to -21.9 mV (drug-loaded micelles). DOX showed significant encapsulation efficiency (71.57% ± 4.855) and drug loading (2.01±0.095). Morphological characterisation through FESEM and TEM revealed the spherical morphology of micelles of both unloaded and loaded micelles. XRD data confirmed the amorphous nature of the formulated drug-loaded micelles. FTIR spectra indicated the proper entrapment of the drug and confirmed no chemical interaction between the drug and the micelles. Drug release profile of the loaded micelles revealed that the colloidal drug carrier could release the drug in a slow manner under normal physiological conditions. Conclusion The present findings implied the potential of overcoming the limitations associated with DOX by formulating DOX-loaded NaCNs against breast cancer.