In the title dinuclear complex, [Tb(2)(C(8)H(7)O(3))(6)(C(12)H(8)N(2))(2)], each Tb(III) ion is eight-coordinated by two N atoms from a 1,10-phenanthroline ligand and six O atoms from the carboxyl-ate groups of five 4-methoxy-benzoate ligands in a distorted square-anti-prismatic geometry. All six 4-methoxy-benzoate ligands act in a bidentate mode, two coordinating to one Tb center each and the other four bridging two Tb centers [Tb⋯Tb separation = 4.3144 (6) Å]. In the crystal, inter-molecular π-π inter-actions between the aromatic rings of 1,10-phenanthroline and 4-methoxy-benzoate ligands [centroid-centroid distance = 3.742 (9) Å] link two mol-ecules into a centrosymmetric dimer. Weak inter-molecular C-H⋯O hydrogen bonds help to consolidate the crystal packing.