To investigate the directional dependence of the Faraday effect in terbium–scandium–aluminum garnet (TSAG) single crystals, grown by the Czochralski method, the Verdet constant was measured at 〈111〉, 〈110〉, and 〈100〉 orientations. Extinction ratio and magnetic susceptibility were measured. From the linear dependence of the Verdet constant and inverse wavelength square 1/λ2, 〈111〉 direction shows the highest value of Verdet constant (for λ⋅ = 649.1 nm, Vav = 8.256 × 10−3 deg · Oe−1 · cm−1). Significant anisotropy of magnetic susceptibility was not observed. The extinction ratio of TSAG shows the highest value for 〈111〉 orientation 38.7 dB, which implies that it can be used as an optical isolator.