We fabricate a free-standing few-layer molybdenum disulfide (MoS₂)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1, 535 nm to 1, 565 nm, are generated, corresponding to photon energies below the MoS₂ material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications.