The 58th/59th Battalion was an infantry battalion of the Australian Army which served during the Second World War. Raised in 1942 as part of the Militia through the amalgamation of the 58th and 59th Battalions, it formed part of the 15th Brigade, assigned to the 3rd Division. Initially the battalion undertook defensive duties in Australia before being deployed to New Guinea where it took part in the fighting around Salamaua and Lae and then the Finisterre Range campaign. In 1945 they were sent to Bougainville where they took part in the fighting in the southern sector of the island. Following the end of the war, the battalion was disbanded in 1946.