Organic nitroxide radicals – specifically chloro-, bromo, and iodo-substituted nitronyl nitroxides – exhibit self-assembly in crystalline states through the combined action of halogen (Hal···ONO) and hydrogen (ONO⋯HMe) bonds. Theoretical calculations reveal that halogen bonds primarily govern the association of these nitroxides. This halogen bonding facilitates the proximity of atoms carrying spin densities of opposite signs, thereby promoting ferromagnetic intermolecular exchange interactions. This research demonstrates, for the first time, that halogen bonding can establish channels facilitating ferromagnetic intermolecular exchange between paramagnetic centers in organic nitronyl nitroxide radicals. This breakthrough discovery expands the potential applications of halogen bonding in the supramolecular modulation of magnetic properties within high-spin clusters—a function that was previously attributed exclusively to hydrogen bonding.