In the title salt, [Fe(C(12)H(8)N(2))(3)][Fe(2)Cl(6)O], the ionic components are linked into a two-dimensional supra-molecular layer by two pairs of C-H⋯Cl hydrogen bonds and π-π stacking inter-actions [centroid-centroid distances = 3.655 (4) and 3.498 (3) Å]. The salt is characterized as a mixed-valent Fe(II)-Fe(III) compound, in which an Fe(II) atom is coordinated by three phen ligands, forming a six-coordinated cationic entity and the anionic part is formed by two Fe(III) atoms in tetra-hedral coordination environments constructed by three chloride ions and one bridging oxide ligand. Intra-molecular C-H⋯N hydrogen bonds are observed.