Abstract: A waterproof LED luminaire is provided, which mainly comprises a lamp holder, a light emitting diode module, a cover plate, a first side cover and a second side cover. Each of the first side cover and the second side cover has a waterproof groove provided on its inner wall surface. When both side covers are respectively assembled on both sides of the lamp holder, both the side edges of both sides of the lamp holder are fitted respectively with the waterproof grooves in such a manner that liquid can be prevented from infiltrating into the interior of the lamp holder. Therefore, the overall waterproof performance of the present invention can be enhanced.