High-quality tungsten disulfide (WS₂) nanosheets are fabricated by thermal decomposition method and successfully used as a saturable absorber (SA) for passively Q-switched Nd  :  GdVO₄ laser operating at 1063 nm. The nonlinear optical measurements of the WS₂ nanosheets reveal efficient saturable absorption properties at 1  μm showing a modulation depth of 9% and a saturation intensity of 89.87  μJ  /  cm². The maximum average output power of 1.2 W is obtained with the shortest pulse width of 57.96 ns and the highest repetition rate of 1.11 MHz. The results indicate that WS₂ nanosheets could be an excellent SA for high repetition rate and high peak power laser generation.