Herein, we report the first synthesis of multidentate carborane-based halogen bond donors, investigations on their Lewis acidity in solution, and their application in organocatalysis. To this end, we designed bidentate halogen bond donors m-1 and p-1 (Figure ), which are topologically related to our earlier catalysts m/p-2, and the analogous tridentate variant 3 (which resembles 4). The new carborane-based catalysts not only reached the performance of the earlier perfluorinated variants but markedly surpassed it in a benchmark halide abstraction reaction. This allowed us to successfully use the strongest halogen bond donor 3 in a nitro-Michael addition reactionwhich was previously out of reach for neutral XB-based organocatalysts.