Disclosed herein is a glass composition that includes, based on the total weight of the composition, 52 wt % to 58 wt % of SiO2, 12 wt % to 16 wt % of Al2O3, 16 wt % to 26 wt % of B2O3, greater than 0 wt % and not greater than 2 wt % of MgO, 1 wt % to 6 wt % of CaO, greater than 1 wt % and lower than 5 wt % of TiO2, greater than 0 wt % and not greater than 0.6 wt % of Na2O, 0 wt % to 0.5 wt % of K2O, 0 wt % to 1 wt % of F2, 1 wt % to 5 wt % of ZnO, greater than 0 wt % and not greater than 1 wt % of Fe2O3; and 0.1 wt % to 0.6 wt % of SO3. Also disclosed herein is a glass fiber including the glass composition.