A polarization-maintaining chalcogenide glass fiber with a ridged core was designed and fabricated using Ge₁₂As₂₄Se₆₄ (Ge-As-Se) glass as the core material and Ge₁₀As₂₄S₆₆ (Ge-As-S) glass as the cladding material for generating linearly polarized mid-infrared supercontinuum (MIR SC). The ridged core fiber's group velocity dispersion was simulated using the finite element method, and the ridged core's geometrical size was determined. A multiple-stage rod-in-tube process paired with an extrusion technique was used to fabricate the fiber. The fabricated fiber exhibits a typical transmission loss of approximately 4 dB/m and a polarization extinction ratio of 19.4 dB-19.6 dB in the 2.9-5.5-μm spectral range. SC ranging from 2 to 9.5 μm with an average power of approximately 4 mW was generated when the fiber with a length of 12 cm was pumped by laser with a central wavelength of 3.7 μm, a pulse width of 170 fs, the repetition rate of 100 kHz, and average power of 40 mW. The SC has a measured polarization extinction ratio of 19.2 dB. These results indicate that the Ge-As-Se/Ge-As-S fiber with a ridged core is a promising nonlinear medium for generating linearly polarized broadband MIR SC.