The application of halogen bonding for catalyst activation is a widely accepted paradigm. However, our DFT mechanism study on two representative reactions, previously considered to be catalyzed through halogen bonding interactions (N-F•••N=C or I-I•••O=C/C=C), reveals the involvement of halogen cation transfer from halogen bonding donors to substrates. This alternative mechanism is consistent with previously observed reactivity and selectivity, and is further supported by control experiments. Our DFT studies have uncovered halogen-cation transfer as a new mode of C=N and C=C activation; the widespread use of these functional groups in novel substrate synthesis and new reaction design indicates halogen cation transfer organocatalysis have significant untapped potential to open up new avenues of chemical synthesis. Further research in our laboratories is underway to explore the broader implications of developing and exploiting new halogen cation transfer organocatalysis with novel applications in organic synthesis.