The face-sharing bioctahedral molybdenum(VI) oxide fluoride anion [Mo2O6F3](3-) has been isolated in the new compound [Cu(3-apy)(4)](3)(Mo2O6F3)(2) (3-apy = 3-aminopyridine) and has been characterized by experimental and computational techniques. Single-crystal X-ray diffraction studies show that the structure of the [Mo2O6F3](3-) anion resembles two distorted face-sharing octahedra, each with three short terminal metal-ligand bonds and three long metal-ligand-metal bridging interactions. Aspects of the electronic structure, as well as geometric comparisons of the bond lengths and angles in [Mo2O6F3](3-) with those in the similarly distorted [MoO3F3](3-) anion, suggest that the six terminal ligand positions of the confacial bioctahedra are occupied exclusively by oxide ligands and that the three bridging sites are occupied by fluorides. Crystal data for [Cu(3-apy)(4)](3)(Mo2O6F3)(2): trigonal space group R (3) over bar (No. 148) with hexagonal axes of a = 13.881 (1) angstrom and c 31.783(3) angstrom (Z = 3).