A modular deck drain system comprising a bottom channel and an upper cover. The bottom channel has a pair of opposed side walls and a bottom surface coupled to the side walls. The bottom channel also has a plurality of stabilizing members coupled to and extending from an external surface of the bottom channel, and at least one modular junction node. The upper cover is configured to couple to the bottom channel. The upper cover has two upper walls, each wall having a top end and a bottom end, and the top end of each wall is coupled to an upper lip. A narrow top opening is formed by the upper lips. The upper cover has at least one cutline.