Reaction of 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride (HATP·6HCl) and (TpPhNi)Cl (TpPh = tris(3,5-diphenyl-1-pyrazolyl)borate) produces the radical-bridged trinickel complex [(TpPhNi)3(HITP)] (HITP3-˙ = 2,3,6,7,10,11-hexaiminotriphenylene). Magnetic measurements and broken-symmetry density functional theory calculations reveal strong exchange coupling persisting at room temperature between HITP3-˙ and two of the three Ni2+ centers, a rare example of strong radical-mediated magnetic coupling in multimetallic complexes. These results demonstrate the potential of radical-bearing tritopic HITP ligands as building blocks for extended molecule-based magnetic materials.