In the following study, preparation of nano adsorbent from carboxymethyl cellulose (CMC) was carried out by introducing sulfonate group on CMC to prepare sulfonated carboxy methyl cellulose (SCMC). The polymer was used for adsorptive removal of cationic dyes crystal violet (CV) and methylene blue (MB) as models. The produced nanostructure and morphology of the SCMC were investigated by Transmission Electron Microscopic (TEM), Fourier transform infrared (FT-IR) spectroscopic analyses, scanning electron microscopy (SEM), and Zeta potential. Adsorption characteristics of the SCMC for removal of both cationic dye were investigated spectrophotometrically as a function of initial dye concentration and contact time, adsorbent dosage, solution pH, and temperature. The maximum adsorption capacities of the SCMC nanoparticle-based adsorbent for both MB and CV were described by the equilibrium adsorption data of both dyes, which fitted well with the Langmuir model (R2 = 0.998 for MB dye) but for CV the equilibrium data fitted well with Elovich model (R2 =(0.9961). The kinetics of adsorption followed the pseudo-first-order model. The adsorption process is spontaneous and endothermic, according to thermodynamic studies conducted at temperatures ranging from 298 to 313 K. When the parameters are tuned, the adsorbent can remove both dyes quickly and with a high level of efficiency.