The synthesis of high-crystalline few-layer MoS₂ films is crucial for the development of 2D TMDs (MoS₂) based high-performance electrical and optoelectronic devices. The present work reports on a study of thermal annealing and ion-beam induced annealing to improve the crystallinity of few-layer MoS₂. According to XRD and TEM measurements, the annealing temperature for few-layer MoS₂ in Ar-gas environments was 300 °C, resulting in high crystallinity in a uniform manner. The crystallinity of the few-layer MoS₂ decreases as the annealing temperature is increased beyond 300 °C. TEM observations also show that the MoS₂ flake size reduces with increasing annealing temperature. In-situ XRD measurements show the ion-beam induced annealing in MoS₂ under 120 MeV Au ion-irradiation. The crystallinity improves with lower ion fluence (1 × 10¹⁰ ions/cm²), whereas it leads to damage at higher fluences.