The present invention provides a high alumina fused cast refractory that is easily produced and has low porosity and high corrosion resistance, and a method of producing the same. The high alumina fused cast refractory of the present invention has the following chemical composition: 95.0 mass % to 99.5 mass % Al2O3, 0.20 mass % to 1.50 mass % SiO2, 0.05 mass % to 1.50 mass % B2O3, 0.05 mass % to 1.20 mass % MgO and balance. The method of producing the high alumina fused cast refractory of the present invention includes obtaining a mixture by mixing an Al2O3 source material, a SiO2 source material, a B2O3 source material and an MgO source material, and fusing the mixture.