In the title compound, (C(12)H(12)N(2))[Ta(2)F(10)O], the doubly protonated 5,6-dihydro-1,10-phenantroline-1,10-diium cation is located on a twofold rotation axis, whereas the isolated [Ta(2)OF(10)](2-) dianion has -1 symmetry. In the so far unknown dianion, the symmetry-related Ta(V) atoms are octa-hedrally coordinated by five F atoms and a bridging O atom, the latter being located on an inversion centre. The two pyridine rings in the cation make a dihedral angle of 22.8 (4)°. The cations and dianions are arranged in layers parallel to (100) and are connected through N-H⋯F and C-H⋯F hydrogen-bonding inter-actions into a three-dimensional structure.