Herein, structural, surface area, optical, photocatalytic, and magnetic properties of a new Cd1–xSnxFe2O4 nanocomposites (1 ≥x ≥0), synthesized by the hydrothermal approach were investigated. The nanocomposite formation is confirmed by X-ray diffraction analysis (XRD), Transmission electron microscopes (TEM), Fourier transform infrared (FTIR), Inductively coupled plasma (ICP), and Energy dispersive X-ray (EDX) analyses. The XRD findings reveal the formation of Fe2O3 at x =0, 0.2, 0.4, and 1, while the Fe3O4 phase at x =1 besides the spinel CdFe2O4 phase for x =0.6 and 0.8, and rutile SnO2 phase for x ≥0.8. The crystal structure, e.g., lattice parameters, bond length, cell volume, theoretical density, crystallite size, dislocation density, and microstrain are remarkably influenced by elemental ratios. The average crystallite size of composites declined to 15.2 ±4 nm as x increased to 0.4, then grew to 40.5 ±4 nm at x =0.6, and then decreased to 21 ±10 nm at x =1. The particle morphologies were deduced, and crystal structures were confirmed by analyzing field-emission scanning electron microscope (FE-SEM), and TEM micrographs. FTIR confirmed the presence of metal oxide bands for all nano composites. The surface area was calculated via the Brunauer–Emmett–Teller (BET) and Barrett-Joyner-Halenda (BJH) theories to the N2 adsorption–desorption isotherm and equals 10.5, 20.3, 17.1, and 25.2 m2/g at x =0, 0.4, 0.6, and 1, respectively. The magnetic properties of the Cd1–xSnxFe2O4 nanocomposites were studied by vibrating-sample magnetometry (VSM) technique, which displayed their ferromagnetic behaviors. The addition of Sn2+into the composite improved the magnetic saturation from 0.42 to 34.7 emu/g by changing x from 0 to 0.4 then was reduced to 5.9 emu/g at x =1 which well matched with the behavior of total pore volume. Furthermore, the indirect optical band gap (Ein g ) was increased, e.g., Ein g equals 1.22, 1.82, 1.88, and 2.08 eV for x =0, 0.4, 0.6, and 1, respectively. Methylene blue photocatalytic performance was investigated, and the max imumdegradation efficiency of 44.33 %was detected using Cd1–xSnxFe2O4 at x =0.8 under UV–visible irradi ation for 160 min.