Anizah or Anazah (Arabic: عنزة, romanized: ʻanizah, Najdi pronunciation: [ʕni.zah]) is an Arabian tribe in the Arabian Peninsula, Upper Mesopotamia, and the Levant.

Anizah's existence as an autonomous tribal group, like many prominent modern tribes, predates the rise of Islam in the seventh century. The classical Arab genealogists placed Anizah within the large Rabiʿa branch of the Adnanites alongside the tribes of Abd al-Qays, Banu Bakr, Bani Hanifa, and Taghlib. In the genealogical scheme, Anizah's eponymous ancestor is a great uncle of all of these.

Two main branches of Anizah are recorded by the early historians. One branch was nomadic, living in the northern Arabian steppes bordering Syria and Mesopotamia. The other, was sedentary, living within the wadis of the district of Al-Yamama in eastern Najd, just south of their purported cousins, the Bani Hanifa of the Banu Bakr, who inhabited modern-day Riyadh. One of these clans Bani Hizzan, Families tracing their origin to Anizah through Hizzan still exist in that area today.

The other tribes of Rabiʿa were far more prominent in the events of late pre-Islamic Arabia and the early Islamic era. According to historians such as al-Tabari (10th century), the Anizah joined with Bakr ibn Wa'il under an alliance they called al-Lahazim. Many of these tribes were followers of the Christian faith prior to Islam. Others such as bani Taghlib remained largely Christian even after the Muslim conquest of Mesopotamia and the Levant.

Bahrain's House of Khalifa and Kuwait's House of Sabah royal families both trace their ancestry to this vast tribe. Saudi Arabia's House of Saud trace their ancestry to Anizah's cousin tribe, the Bani Hanifa, which has merged with the larger tribe Anizah, and are therefore considered members of it as well.

According to the historians al-Hamdani and Abu'l-Hasan Bayhaqi, the Anizah tribe settled in the Hijaz region, specifically in Khaybar, at the end of the 10th century AD. The Uyunid prince and poet Ali bin al Mugrab Al Uyuni mentioned the news of the Anizah tribe fighting rulers of Khaybar, the descendants of Ja'far al-Tayyar, and expelled them from it. With the passage of time, a part of the Anizah become urban, while the other part remained on the nomadic lifestyle.

The 13th-century historian Ibn Sa'id al-Maghribi says about himself that he came to the Arabian Peninsula and asked about the rest of the Rabi’a tribes, saying about that 'I entered the Arabian Peninsula and asked: Are there any Rabi'ah tribes left in its regions? They said: There is no one left who rides horses, settles and migrates except for the Anazah, and they are in the regions of Khaybar, and the Banu Shu'bah are famous for highway robbery and tearing down veils in the outskirts of the Hijaz near Yemen and the sea, and the Banu Anz are in the region of Tabalah; and other than that we do not know of in the East or the West'".

The 14th-century historian Ibn Fadlallah al-Umari notes that the Anazah were one of the tribes allied with the Al Fadl, along with several other tribes, the most prominent of which were Khath'am, Adwan, and Dhafeer.