A vehicle underfloor structure includes under covers (3, 4, 5, 6, 7) that cover an underside of a vehicle, and drain members (D) provided in the under covers (3, 4, 5, 6, 7). The drain members (D) each include: a front inclined wall (21) provided with a water drain opening (33, 34, 42, 43, 44, 72, 74); and a rear inclined wall (22). A recess is formed in each under cover in a front-back direction of the vehicle in such a manner that a first interior angle (θ1) formed by the front inclined wall is larger than a second interior angle (θ2) formed by the rear inclined wall and a length of the front inclined wall is different from a length of the rear inclined wall.