Abstract: A fiber optic bundle interface cooling system and apparatus is provided. Optical fibers are in part enclosed in a chamber, with the bundle interface facing a windowed wall. A separation plate with apertures is spaced apart from the bundle interface, and the optical fibers extend through the apertures. Fluid enters the chamber and passes through the interstitial channels of the bundle interface to remove heat, and exits the chamber. The apparatus for cooling a FO bundle interface has a chamber with a separation plate, a windowed wall, and a fiber optic clamp for holding the bundle interface in place. A pump is operatively connected to the chamber for moving fluid.