We report, for the first time to our knowledge, an all-fiber wavelength-swept Tm-doped laser based on a fiber Fabry–Perot tunable filter in the $2\mathrm{\mu m}$ spectral region. The laser wavelength can be continuously tuned over $200\mathrm{nm}$ from 1840 to $2040\mathrm{nm}$ in a short period of time. The demonstrated tuning speed was $12.5\mathrm{\mu m}/\mathrm{s}$ with a tuning efficiency of $17.5\mathrm{nm}/\mathrm{V}$ . The spectral linewidth of the laser was measured to be approximately $300\mathrm{MHz}$ or $0.01{\mathrm{cm}}^{-1}$ . This kind of laser can find potential applications in both high-resolution laser spectroscopy and tunable mid-IR generation via nonlinear frequency conversion.