The title mononuclear Cu(II) complex, [Cu(C9H7O2)2(C12H8N2)], is comprised of a Cu(II) cation, two cinnamate (L (-)) ligands and a 1,10-phenanthroline (phen) ligand. The Cu(II) atom and phen ligand lie on a twofold rotation axis. The Cu(II) atom is coordinated by two O atoms from two carboxyl-ate groups of two (L (-)) ligands and two N atoms from one phen ligand, exhibiting a distorted square-planar geometry. In the crystal, mol-ecules are assembled into supra-molecular chains parallel to the c axis through weak C-H⋯O hydrogen bonds involving the phen and cinnamate ligands.