The sulfuric acid leaching of titania slag produced by semi-molten state reduction of Panzhihua ilmenite concentrate followed by magnetic separation is studied. The titanium-bearing phase of the slag is mainly composed of anosovite (MxTi3-xO5, 0 ≤ x≤2, M represents: Ti, Fe, Mg, Mn, and Al) and M2O3 solid solutions. The titania slag was leached in two stages using sulfuric acid, with the second stage using a stronger acid, a higher acid to solid ratio, and smaller particles to further leach the titanium. The results showed that the overall acidolysis ratio of titanium in the titania slag with additive-free, addition of sodium carbonate, and addition of sodium sulfate is 0.90, 0.81, and 0.89 respectively. It was found that fine grinding of the titania slag is beneficial to the leaching of titanium. The overall recoveries of titanium in the novel process after sulfuric acid leaching for the additive-free, Na2CO3-added, and Na2SO4-added slags are 0.61, 0.76, and 0.79, respectively. The phase and morphology of the raw titania slag and leaching residue related to the leaching behaviour were also characterised.