<p>A systematic study of the structural, microstructural, and dielectric properties of dysprosium (Dy) and manganese (Mn) co-doped cobalt ferrite with the chemical formula Co_{(1−<i>x</i>)}Dy_<i>x</i>Fe_{(2−<i>y</i>)}Mn_<i>y</i>O₄ (where <i>x</i> = <i>y</i> = 0, 0.05, 0.1, 0.15, 0.2, and 0.25) nanopowders was conducted using the sol–gel autocombustion method. The formation of the cubic spinel phase was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) experiments. The Williamson–Hall (W–H) plot was used to determine particle size and micro-strain for all the samples. The FTIR results for all undoped and co-doped samples generated revealed a metal oxide band with a wave number between 524 and 549&#xa0;cm⁻¹, indicating cobalt ferrite nanoparticles. Morphology studies using scanning electron microscopy and energy dispersive X-ray analysis show well-grown grains with intergranular pores and clear grain boundaries, as well as the presence of all elements responsible for the constituent sample’s&#xa0;formation. Dielectric experiments were performed on all synthesized specimens in terms of frequency and temperature. At the frequencies and temperatures examined, typical space charge polarization was seen, along with significantly reduced dielectric losses. All co-doped samples showed distinct differences in all structural, microstructural, and dielectric investigations based on their co-doping elements compositions. All conceivable explanations for the typical changes in the lattice of cobalt ferrite were thoroughly investigated in terms of theoretical issues and are described here. Cobalt ferrite has been employed in a variety of applications, such as sensor, actuator, catalysis, energy storage, medical devices, magnetic hyperthermia in the biomedical field, and drug delivery systems, due to its extensive magnetic and electric properties.</p>