The synthesis and characterization of a novel triazine anion pentafluoroosmium(VI) complex are presented. The single crystal determination of the title compound (hereafter denoted 1) was carried out at −140 °C. Compound 1, C3F4N3OsF5, crystallizes in the monoclinic space group, P21/n, with unit cell dimensions: a = 8.6809(17) Å, b = 7.6848(15) Å, c = 12.415(3) Å, β = 102.633(4)°, V = 808.2(3) Å3, and Z = 4. Synthesis, characterization, X-ray diffraction study along with the crystal supramolecular analysis of the title complex were carried out. The complex contains the anionic triazine unit C3N3F4− acting as a mono dentate ligand to osmium(VI) with five fluoro ligands in a slightly distorted octahedral geometry around osmium(VI) ion (osmium is denoted as Os). The C3N3F4−, triazine anion ring deviates from planarity, only with the C1 being tetrahedral. The crystal lattice of the title compound displays significant intermolecular X···X interactions, namly F···F, F···N and F···C. All types of X···X bonding consolidate to form a three-dimensional network.