A modular helmet interface with a mounting cleat and adhesive layer is provided. In one aspect, a mounting cleat is affixed to a helmet, such as a ballistic helmet, by an adhesive layer, the mounting cleat having a cavity filled with the adhesive used to secure the cleat to the helmet. In a further aspect, the mounting cleat has one or more annular grooves for improving the bond between the cleat and the helmet. In another aspect, a mounting cleat is secured to a helmet by way of a cleat-receiving securing member, the securing member affixed to the helmet by an adhesive layer.