The Territory of Papua was an Australian possession comprising the southeastern quarter of the island of New Guinea, existing from roughly 1902 to 1949. It had previously been administered from London as British New Guinea. The territory now forms the southern part of Papua New Guinea, and makes up roughly half of that country.

The territory became a British protectorate on 6 November 1884, together with some adjacent islands. On September 4, 1888 it was annexed by Britain as British New Guinea. (The northern part of modern Papua New Guinea, then known as German New Guinea had been under German commercial control since 1884 and passed to direct rule by the German government in 1899).

In 1902, Papua was effectively transferred to the authority of the new British dominion of Australia. With the passage of the Papua Act of 1905, the area was officially renamed the Territory of Papua and Australian administration became formal in 1906.

Shortly after the start of the Pacific War, the island of New Guinea was invaded by the Japanese. Papua was the least affected region. Most of West Irian (at that time known as Dutch New Guinea) was occupied, as were large parts of the Territory of New Guinea (the former German New Guinea, which was also under Australian rule after World War I), but Papua was protected to a large extent by its southern location and the near-impassable Owen Stanley Ranges to the north. Civil administration was suspended during the war and both territories (Papua and New Guinea) were placed under martial law for the duration.

Post-war, the Papua and New Guinea Act (1949) united the Territory of Papua and the Territory of New Guinea as the Territory of Papua and New Guinea, which later became the fully independent Papua New Guinea.