Bahariya Oasis (Arabic: الواحات البحرية, romanized: El-Wāḥāt El-Baḥrīya, "the Northern Oases") is a depression and a naturally rich oasis in the Western Desert of Egypt. It is approximately 370 km away from Cairo. The roughly oval valley extends from northeast to southwest, has a length of 94 km, a maximum width of 42 km and covers an area of about 2000 km².

The valley is surrounded by mountains and has numerous springs. Located in Giza Governorate, the main economic sectors are agriculture, iron ore mining, and tourism. The main agricultural products are guavas, mangos, dates, and olives.

In Ancient Egypt, the oasis had two names. The name 'ḏsḏs' (Djesdjes) is first mentioned on a scarab dating back to the Middle Kingdom. In the New Kingdom, this name is rarely found, although it does appear for example in the Temple of Luxor and in the account of King Kamose, who occupied the oasis during the war against the Hyksos. From the 25th Dynasty it was almost the only name used. Another name wḥꜣt mḥtt ("the Northern Oasis") was almost exclusively used in the New Kingdom; it appears for instance on the local grave of Amenhotep, and is found again in the list of oasis in the Temple at Edfu.^{[citation needed]}

From 45 CE, the depression was known in Latin as Oasis parva (Small Oasis). The Greek historian Strabo called it the "Second Oasis", and the 5th century CE historian Olympiodorus of Thebes called it "the Third Oasis".

In Coptic times, it was known as the "Oasis of Oxyrhynchus" (Coptic: ϯⲟⲩⲁϩ `ⲙⲡⲉⲙϫⲉ Diwah Ēmbemdje) or Tast(s) (Coptic: ⲧⲁⲥⲧ(ⲥ)), which is derived from Ancient Egyptian ḏsḏs. After the Islamization of Egypt, it was called the Oasis of Bahnasa, "Oasis of Oxyrhynchus".^{[citation needed]}

The modern name is الواحات البحرية, al-Wāḥāt al-Baḥriyya meaning "the Northern Oases". The southern part of the depression around El Heiz apparently never had a separate name.^{[citation needed]}

Bahariya consists of many villages, of which El Bawiti is the largest and the administrative center. Qasr is el-Bawiti's neighboring/twin village. To the east, about ten kilometers away are the villages of Mandishah and el-Zabu. A smaller village called el-'Aguz lies between El Bawiti and Mandishah. Harrah, the easternmost village, is a few kilometers east of Mandishah and el-Zabu. El Heiz, also called El-Hayez, is the southernmost village, but it may not always be considered as part of Bahariya because it is so far from the rest of the villages, about fifty kilometers south of El Bawiti. There is an oasis at El-Hayez where mummies have been found on which genetic studies have been conducted.

The depression has been populated since the Neolithic, although archaeological evidence is not continuous. In El Heiz, a prehistoric settlement site of hunter-gatherers was found with remains of grindstones, arrowheads, scrapers, chisels, and ostrich eggshells. In Qārat el-Abyaḍ, a Czech team led by Miroslav Bárta discovered a settlement of the Old Kingdom. Rock inscriptions in el-Harrah and other records date to the Middle Kingdom and upwards. The tomb of Amenhotep called Huy was erected in Qarat Hilwah at the end of the 18th dynasty. In the 26th dynasty, the depression was culturally and economically flourishing. This can be learned from the chapels in 'Ain el-Muftilla, the tombs in Qārat Qasr Salim and Qarat esh-Sheikh Subi, and the site of Qasr 'Allam.