Dibenzodiazepines and organoselenium compounds represent important structural motifs with broad applications in pharmaceuticals and materials science. Herein, we describe an electrochemical selenylative cyclization strategy for the efficient synthesis of selenylated dibenzodiazepines at room temperature. Utilizing stable diselenides as the selenium source and isocyanides as a C1 synthon, a series of organoselenyl dibenzodiazepine derivatives were smoothly synthesized with up to 81% yield, demonstrating excellent functional group compatibility and high atom efficiency.