The Battle of Wakde (Operation Straight Line) was part of the New Guinea campaign of World War II. It was fought between the United States and Japan from 17 May 1944 to 21 May 1944 in Dutch New Guinea. The operation involved an assault on the Japanese-held Wakde island group by a reinforced US infantry battalion, which was transported from a beachhead the Allied troops had established around Arara, on the mainland, the previous day. Following the capture of the island, fighting on the mainland continued until September as Allied troops advanced west towards Sarmi. In the aftermath, the island's airbase was expanded and used to support operations around Biak and in the Marianas.

The New Guinea campaign of the Pacific War lasted from January 1942 until the end of the war in August 1945. During the initial phase in early 1942, the Empire of Japan invaded the Territory of New Guinea on 23 January and Territory of Papua on 21 July and overran western New Guinea beginning on 29 March. During the second phase, lasting from late 1942 until the Japanese surrender, the Allies—consisting primarily of Australian forces—cleared the Japanese first from Papua, then New Guinea, and finally from the Dutch colony.