The Battle of Slater's Knoll (28 March – 6 April 1945) was a battle fought between Australian and Japanese forces on Bougainville Island during the Second World War. Part of the Bougainville campaign, the battle occurred as a force of about 3,300 Japanese from the Japanese 6th Division, including artillery and other supporting elements, launched a counterattack against the main Australian offensive which had been pushing south towards Buin, concentrating their attacks on Slater's Knoll near the Puriata River. The Australian troops belonged to the 7th Brigade, with the 25th Infantry Battalion being the most heavily engaged, although the 9th Infantry Battalion and the 61st Infantry Battalion also took part in the fighting.