In the mononuclear title compound, [Tb(C(13)H(9)OS(3))(3)(C(4)H(8)O)(3)]·C(4)H(8)O, the lanthanide cation is located on a threefold rotation axis and is surrounded by electron-rich ligands in an approximately octa-hedral geometry. One of the thienyl groups and the bound THF are disordered with 0.5:0.5 occupancy. The free THF is disordered around the threefold axis.