This work presents a method for material characterization of thin laminates that utilizes an inverse procedure, based solely on the laminate’s natural frequencies, to identify its engineering constants. The key strength of the method lies in its generality: it can be applied to isotropic, orthotropic, or anisotropic plates. Unlike other classical identification techniques (such as static tests), dynamic methodologies offer several advantages, including being non-destructive and providing mechanical properties representative of the entire material rather than of localized areas. Furthermore, the reliability of vibrational measurements and their ease of acquisition are well-established in the literature, making these techniques even more appealing. The strategy relies on determining a relatively large set of natural frequencies of the plate using experimental modal analysis techniques, which are then compared to the corresponding set of numerically calculated frequencies, derived from a model of the plate based on classical plate theory. The material constitutive parameters are then identified by minimizing the discrepancy between the experimental and numerical frequencies. By validating the method through an experimental campaign conducted on isotropic aluminium and orthotropic PLA plates, it is shown that it is possible to determine, with reasonable accuracy, the Young's modulus, the Poisson's ratio, the shear ratio, and even the fibre orientation angle using only the natural frequencies of the plate as input.