An internal combustion engine includes a cylinder block, a cylinder-block passage, a cylinder head, a cylinder-head passage, cylinders, an introducing portion, a restricting wall, and communicating portions. The introducing portion is configured to introduce coolant flowing in the cylinder-head passage into an EGR cooler. The restricting wall is configured to restrict flow of the coolant from a section corresponding to the spark plug toward the introducing portion. The communicating portions cause the cylinder-block passage and the cylinder-head passage to communicate with each other. A direction perpendicular to both the extending direction of the central axis of each cylinder and the cylinder arrangement direction is defined as a predetermined direction. Certain one or certain ones of the communicating portions are arranged at positions closer to an intake manifold than the restricting wall in the predetermined direction.