World War II: American troops force the Japanese from their positions east of the Matanikau River during the Battle of Guadalcanal.

The Actions along the Matanikau—sometimes referred to as the Second and Third Battles of the Matanikau—were two separate but related engagements between the United States and Imperial Japanese naval and ground forces in the Pacific theater of World War II. The actions occurred around the Matanikau River on Guadalcanal Island in the southwestern Pacific 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.