Equatoria is the southernmost region of South Sudan, along the upper reaches of the White Nile and the border between South Sudan, Uganda, Kenya, and the Democratic Republic of the Congo. Juba, the national capital and the largest city in South Sudan, is located in Equatoria. Originally a province of Anglo-Egyptian Sudan, it also contained most of northern parts of present-day Uganda, including Lake Albert and West Nile. It was an idealistic effort to create a model state in the interior of Africa that never consisted of more than a handful of adventurers and soldiers in isolated outposts.

Equatoria was established by Samuel Baker in 1870. Charles George Gordon took over as governor in 1874, followed by Emin Pasha in 1878. The Mahdist Revolt put an end to Equatoria as an Egyptian outpost in 1889. Later British Governors included Martin Willoughby Parr. Important towns in Equatoria included Lado, Gondokoro, Dufile and Wadelai. The last two former areas of Equatoria, Lake Albert and West Nile are now situated in Uganda.

Under Anglo-Egyptian rule, most of Equatoria became one of the eight original provinces of Sudan. The region of Bahr el Ghazal was split from Equatoria in 1948. In 1976, Equatoria was further split into the provinces of East and West Equatoria. The region has been troubled with violence during both the First and Second Sudanese Civil Wars, as well as the anti-Ugandan insurgencies based in Sudan such as the Lord's Resistance Army and West Nile Bank Front.

Equatoria consists of the following states:

Between October 2015 and February 2020, Equatoria consisted of the following states:

The people of Equatoria are traditionally peasants or nomads belonging to numerous ethnic groups. They live in the counties of Budi, Ezo, Juba, Kajo-keji, Kapoeta, Magwi, Maridi, Lainya, Mundri, Terekeka, Tombura, Torit, Yambio, and Yei. Equatoria is inhabited by the ethnolinguistic groups listed below. The following tribes occupy the three states of Greater Equatoria: Acholi, Avukaya, Baka, Balanda, Bari, Didinga, Kakwa, Keliko, Kuku, Lango, Lokoya, Narim, Lopit, Lugbwara, Lulubo, Madi, Makaraka or Adio, Moru, Mundari, Mundu, Nyangwara, Otuho, Pari, Pojulu, Tenet, Toposa and Azande. Some of these tribes like Bari, Pojulu, Kuku, Kakwa, Mundari and Nyangwara share a common language, but their accents, and some adjectives and nouns do vary; the same applies to Keliko, Moru and Madi.

Other than Arabic or (Arabi Juba) and English, the following languages are spoken in Equatoria according to Ethnologue.

Due to many years of civil war, the Equatorian culture is heavily influenced by the countries neighboring Equatoria and hosting Equatorians. Many Equatorians fled to Ethiopia, Kenya, Uganda, the Democratic Republic of the Congo, the Central African Republic, Sudan, the United States, Canada, the United Kingdom, Australia and Europe, where they interacted with the nationals and learnt their languages and culture. For most of those who remained in the country, or went North to Sudan and Egypt, they greatly assimilated Arabic culture.