Display omitted •Optical and dielectric properties of l-valine doped ADP crystal.•The SHG efficiency is found to be 1.92 times that of KDP crystal.•High transparency is useful for optoelectronics applications.•The lower dielectric characteristics were ascertained from dielectric measurements.•Third order nonlinearity shows its applications for optical limiting and sensor devices. Single crystal of l-valine doped ammonium dihydrogen phosphate has been grown by slow evaporation method at room temperature. The crystalline nature of the grown crystal was confirmed using powder X-ray diffraction technique. The different functional groups of the grown crystal were identified using Fourier transform infrared analysis. The UV–visible studies were employed to examine the high optical transparency and influential optical constants for tailoring materials suitability for optoelectronics applications. The cutoff wavelength of the title crystal was found to be 280nm with wide optical band gap of 4.7eV. The dielectric measurements were carried to determine the dielectric constant and dielectric loss at room temperature. The grown crystal has been characterized by thermogravimetric analysis. The second harmonic generation efficiency of the grown crystal was determined by the classical Kurtz powder technique and it is found to be 1.92 times that of potassium dihydrogen phosphate. The grown crystal was identified as third order nonlinear optical material employing Z-scan technique using He–Ne laser operating at 632.8nm.