An air intake device for an internal combustion engine of the present invention includes a water discharge passage extending from a bottom surface of a control valve housing part recessed in a housing passage forming part of an air intake passage to an air intake port. The water discharge passage is formed independently from the air intake passage, and includes: a water collection groove recessed in the bottom surface; a water discharge hole formed penetrating a cover of a valve control housing; and a water discharge hole penetrating a flange part of an insert inserted into the air intake port. The downstream end of the water discharge hole is connected to a space defined between an air intake port inner wall surface and an insert cylindrical part.