A passively Q-switched erbium-doped fiber (EDF) laser is proposed and demonstrated utilizing a zirconium disulfide (ZrS₂)-based saturable absorber (SA). ZrS₂ nanosheets are prepared, whose modulation depth, saturation intensity, and nonsaturable absorbance are measured to be 14.7%, 0.34 MW/cm², and 17.4%, respectively. Then, a Q-switched EDF laser is implemented by the ZrS₂-SA. The pulse repetition rate varies from 40.65 to 87.1 kHz when the pump power changes from 55 to 345 mW. The shortest pulse width is 1.49 μs with pulse energy of 33.5 nJ. As far as we know, this is the shortest pulse width obtained by a ZrS₂-SA so far.