Chromophores in azo dyes are optically active and play an important role in modifying the optical nonlinear properties. Methyl orange (MO), an azo dye, has been chosen to dope with l‐arginine monohydrochloride (LAHCl), in order to tune the nonlinear optical properties. Pristine and MO doped LAHCl single crystals are grown by slow solvent evaporation method at ambient conditions. The grown crystals are confirmed by powder X‐ray diffraction and Fourier transform infrared studies. The crystals are subjected to linear and nonlinear optical characterizations. Decrease in optical band gap with increase in refractive index and birefringence are attributed to the increase in net macro‐polarizability of the doped LAHCl. Both pristine and MO doped crystals exhibit reverse saturable absorption (RSA) in Z‐scan measurements. The samples show optical limiting behavior under laser irradiation at 650 nm. The chromophore of MO has a significant role in enhancing RSA and optical limiting behavior of LAHCl.