In this paper, synthesis of tetrakis(carboxyphenyl)porphyrin (TCPP) coated cadmium ferrite (CdFe2O4) nanoparticles by using L-lysine as an anchor is reported for the first time. The ferrimagnetic CdFe2O4 nanoparticles were prepared via the facile self-assembly method of reflux followed by a heating treatment. The obtained magnetic nanoparticles were coated with TCPP in the presence of the amino acid L-lysine by sonication in ethanol and then refluxing for 12 h. The structural characteristics of the products were determined using FT-IR and XRD pattern. Scanning electron microscopy (SEM) images indicated uniform morphologies of the magnetic nanoparticles with an average size of 43 nm. The magnetic properties of the prepared samples were characterized on a vibrant sample magnetometer (VSM) with maximum saturation magnetization values of 65.09 and 46.80 emu/g for nanoparticles and nanoparticle/TCPP. The synthesized products were successfully employed to remove the methylene blue (MB) dye from aqueous solutions by using visible light irradiation. The magnetic CdFe2O4 nanoparticles indicated an enhancement of 13% for photodegradation of MB dye after being sensitized by TCPP.