A clip unit and an edge mount light emitting diode (LED) assembly comprising a clip unit. The clip unit provides a mounting structure for mounting a light source, such as an LED, to an edge of a printed circuit board (PCB). A surface mount LED, for example, can thus be easily mounted to the edge of the PCB so as to project light in a direction normal to the edge surface of the PCB, instead of the typical mounting orientation that allows for the projection of light normal to the primary surface of the PCB. The clip unit includes an anode retention clip and a cathode retention clip which are electrically isolated from one another within an insulative housing portion.