This work reports a green method for the synthesis of aryl selenocyanates via a three‐component reaction of arylboronicacids, Se powder, and trimethylsilyl cyanide (TMSCN) undermetal‐free and additive‐freeconditions. Remarkably, TMSCN acts as not only the substrate, but also the catalyst. Various selenaheterocycles can be also accessed with a catalytic amount of TMSCN.