This study investigates the Raman scattering of single- and few-layered WS₂ as a function of the number of S-W-S layers and excitation wavelengths (488, 514, and 647 nm). The frequency of the A₁g (Γ) phonon mode decreases monotonically with the number of layers. For single-layer WS₂, the 514.5 nm laser excitation generates a second-order Raman resonance involving the longitudinal acoustic mode (LA(M)), which results from the coupling between the electronic band structure and lattice vibrations. First-principles calculations were used to determine the electronic and phonon band structures of single-layer and bulk WS₂, and the reduced intensity of the 2LA mode was computed using the fourth-order Fermi golden rule. The results establish a non-destructive Raman fingerprint for identifying single- and few-layered WS₂ films. The study also reveals that the A1g(Γ) mode softens while the 2LA(M) and E2g(Γ) modes exhibit subtle hardening with decreasing layer number. The double-resonant Raman process, active only in monolayer WS₂, explains the intense 2LA(M) signal at 514 nm. This mechanism may be applicable to characterizing other layered systems.This study investigates the Raman scattering of single- and few-layered WS₂ as a function of the number of S-W-S layers and excitation wavelengths (488, 514, and 647 nm). The frequency of the A₁g (Γ) phonon mode decreases monotonically with the number of layers. For single-layer WS₂, the 514.5 nm laser excitation generates a second-order Raman resonance involving the longitudinal acoustic mode (LA(M)), which results from the coupling between the electronic band structure and lattice vibrations. First-principles calculations were used to determine the electronic and phonon band structures of single-layer and bulk WS₂, and the reduced intensity of the 2LA mode was computed using the fourth-order Fermi golden rule. The results establish a non-destructive Raman fingerprint for identifying single- and few-layered WS₂ films. The study also reveals that the A1g(Γ) mode softens while the 2LA(M) and E2g(Γ) modes exhibit subtle hardening with decreasing layer number. The double-resonant Raman process, active only in monolayer WS₂, explains the intense 2LA(M) signal at 514 nm. This mechanism may be applicable to characterizing other layered systems.