Abstarct: In recent years, there was a اhuge interest in strontium hexaferrite nanoparticles as magnetic nanoparticles with many applications in various areas of physics, chemistry, biosensing, and nanomedicine due to unique magnetic, dielectric and optical properties of these nanoparticles. In this research, we report different properties of un- and doped hexagonal strontium ferrite synethesized by hydrothermal and sol-gel autocombustion methods. Different series of strontium hexaferrite nanoparticle were prepared by nominal composition of Sr1−xCexFe12O19 (x = 0.0, 0.05, 0.1, and 0.15) by hydrothermal process. Also Sr1-xCaxFe12O19 (x = 0.0, 0.05, 0.1, 0.15, and 0.2), Sr1-xCaxFe12-yZnyO19 (x = 0, 0.05, 0.1, 0.15; y = 0, 0.25, 0.5, 0.75), and Sr1-xMgxFe12-yZnyO19 (x = 0, 0.05; y = 0, 0.25, 0.5, 0.75) were synthesized by sol-gel autocombustion method. Finally, their structural, magnetic, optical and dielectric properties were investigated. The X-ray diffraction patterns (XRD) and the Rietveld refinement anlysises of the Sr1−xCexFe12O19 series prapred by hydrothermal method confirmed the formation of the pure nano-crystalline phase of the M-type hexaferrite for all samples( a small CeO2 phase, for the x= 0.15 sample). Fourier transform-infrared (FTIR) spectroscopy measurements confired the formation of the M-type hexaferrite. Field emission-scanning electron microscopy (FESEM) revealed that the prepared samples are nanoparticles that agglomerated in irregular platelets. The hysteresis loops measured at room temperature indicated a decrease in the saturation magnetization with an increase in the Ce content. The band gap dependency on the Ce content using the UV–Vis spectra showed that the band gap energies were in the range of 1.37–1.56 eV. The results obtained from dielectric constant and dielectric loss measurements indicated both have high values in low frequencies and low values in the high frequencies. In the next step, Sr1-xCaxFe12O19 (x = 0.0, 0.05, 0.1, 0.15, and 0.2) samples were synthesized by the sol-gel autocombustion method and sintered at the two temperatures of 900 and 1100 °C. XRD, Rietveld refinement analysis and FT-IR measurements confirmed the formation of M-type hexaferrite phase for all samples. The FESEM images indicated all the prepared hexaferrite samples consiste of agglomerated nanoparticles and plate shape morphology for samples sintered at 1100 °C. The results of magnetic hysteresis loops measurementsrevealed saturation magnetization decreases with increase in Ca content. The coercivities for the samples sintered at 900 °C increased with increase in Ca content, whereas for the samples sintered at 1100 °C, the value decreased. Also, the optical band gaps which were in the range of 1.34-1.65 eV, increased with the increase in Ca content. Dielectric constant () and dielectric loss (tan) values for the samples sintered at 900 °C were less than those for the samples sintered at 1100 °C. Then, Ca/Zn-doped strontium hexaferites Sr1-xCaxFe12-yZnyO19 (x = 0, 0.05, 0.1, 0.15; y = 0, 0.25, 0.5, 0.75) were prepared by autocombustion sol-gel method sintered at 900 °C. Here, except for Sr0.9Ca0.1Fe11.5Zn0.5O19 and Sr0.85Ca0.15Fe11.25Zn0.75O19 samples which had 6% and 11% of the zinc ferrite (ZnFe2O4) secondary phase respectively, the other samples were single phase. The saturation and residual magnetization decreased with the increase in doping concentrationThe coercivity values showed irregular changes with the increase in the amount of calcium and zinc. The band gap values for the samples increased with the increase in the Ca/Zn contents from 1.59 eV to 1.72 eV. Dielectric constant () and loss tan (tan) for all samples showed an irregular variations with the substitution of Ca-Zn cations due to the size of grains and grain boundary effect. Finally Sr1-xMgxFe12-yZnyO19 (x = 0, 0.05; y = 0, 0.25, 0.5, 0.75) samples were prepared by autocombustion sol-gel method sintered at 900 °C. X-ray diffraction and the Rietveld refinement method confirmed the formation of the phase of the M-type hexaferrite. FESEM images showed that the samples consist of particles larger than 100 nm formed by the agglomeration of nanoparticles. The amount of Ms decreased with an increase in the amount of Mg and Zn substitution. Also, the lowest value of Ms was obtained for Sr0.95Mg0.05Fe11.75Zn0.25O19 sample. Coercivity variations with Mg and Zn content were not uniform and the lowest coercivity value was obtained for the Sr0.95Mg0.05Fe11.75Zn0.25O19 sample. The band gap also showed non-uniform changes in terms of the amount of substitution from 1.40 eV for Sr0.95Mg0.05Fe11.75Zn0.25O19 to 1.66 eV for Sr0.95Mg0.05Fe12O19. The dielectric constant () and loss tan (tan) also dropped with Mg cation substitution but it increased with Mg-Zn substitution.