Thin films of thallic oxide Tl2O3 (Ia3, a = 1.0534 nm) were electrodeposited on the three low-index surfaces of single crystal Au (Fm3m, a = 0.4079 nm). Epitaxial films of Tl2O3 with a strong out-of-plane (100) texture were obtained in the case of the (100) and (111) Au substrates, while the film on the (110) Au substrate did not show a preferred out-of-plane orientation. Studies of the in-plane orientation of the films revealed that the large lattice mismatch between Au and Tl2O3 is accommodated by the formation of the coincidence lattices on (100) and (111) Au.