A clip for mounting devices on a hat brim includes a first and second panel. The panels are each resiliently connected to a nose portion and separated by a spacing that tapers to a contact point from the distal portions of the panels to their proximal portions. The second panel has a wedge-shaped portion in which the width of the panel increases from its distal end to its proximal end. The bottom surface of the first panel is concave, the preferable concavity being close to that of the curvature of a hat brim. The top surface of the second panel is convex. The preferable convexity is close to that of the curvature of the brim. The top surface of the second panel includes a channel adapted to receive the fabric border of the undersurface of a hat brim. The top surface of the first panel includes at its proximal end structure adapted to receive an accessory device.