The Actions along the Matanikau—sometimes referred to as the Second and Third Battles of the Matanikau—were two separate but related engagements, which took place in the months of September and October 1942, among a series of engagements between the United States and Imperial Japanese naval and ground forces around the Matanikau River on Guadalcanal (island in the south-western Pacific, northeast of Australia) during the Guadalcanal Campaign. These particular engagements—the first taking place between 23 and 27 September, and the second between 6 and 9 October—were two of the largest and most significant of the Matanikau actions.