The idea of incorporating a novel counter anion group with the organic stilbazolium cation (C16H19N2+) yields a new third harmonic generation active single crystal of 4‐[2‐(4‐Dimethylamino‐phenyl)‐vinyl]‐1‐methyl‐pyridinium 2‐Nitroaniline‐4‐sulfonate (DSNA). The slow evaporation solution growth technique is employed to obtain DSNA crystals, whose nonlinear responses are analyzed through a continuous wave laser Z scan experiment. The thermally induced strong reverse saturation absorption and self‐defocusing behaviour of DSNA crystal infers the aptness of the material as an optical limiting device. Optical characterization outcomes imply that the lower absorption edge falls in the visible region (530 nm), with a broad transparency range of 0.53 to 1 μm. Exploration of other optical constants, extinction coefficient (k = 10‐4), emission wavelength (620 nm – red light), optical (σopt = 1010 Ωm‐1) and electrical conductivity (σelc = 1011 Ωm‐1) also concludes that DSNA crystal is a possible applicant for optoelectronic devices. The various bonds and corresponding lengths and angles involved in the formation of DSNA ionic crystal are evaluated by means of the Single Crystal X‐Ray Diffraction (SCXRD) technique. Linear and nonlinear optical property findings undoubtedly affirm that the titular DSNA crystal is an effectual Nonlinear Optical (NLO) crystal.