Karakalpakstan, officially the Republic of Karakalpakstan, is an autonomous republic of Uzbekistan. It spans the northwestern portion of Uzbekistan. Its capital is Nukus (Nókis / Нөкис). Karakalpakstan has an area of 166,590 km² (64,320 sq mi), and has a population of about 2 million people. Its territory covers the classical land of Khwarazm, which in classical Persian literature was known as Kāt (کات).

The name Karakalpakstan means "land of the Karakalpaks". Although most Karakalpaks reside in Uzbekistan, Karakalpak culture and language are closer to those of the Kazakhs and Nogais.

From about 500 BC to 500 AD, the region of what is now Karakalpakstan was a thriving agricultural area supported by extensive irrigation. It was strategically important territory and fiercely contested, as is seen by the more than 50 Khorezm fortresses which were constructed here. The Karakalpak people, who used to be nomadic herders and fishers, were first recorded by foreigners in the 16th century. Karakalpakstan was ceded to the Russian Empire by the Khanate of Khiva in 1873.

Under Soviet rule, it was an autonomous area within the Russian Soviet Federative Socialist Republic before becoming part of Uzbekistan in 1936 as the Karakalpak ASSR.

The region was probably at its most prosperous in the 1960s and 1970s, when irrigation from the Amu Darya was being expanded.^{[citation needed]} However, the evaporation of the Aral Sea has made Karakalpakstan one of Uzbekistan's poorest regions.

The region is suffering from extensive drought, partly due to climate patterns, but also largely because the Amu Darya and Syr Darya rivers are mostly diverted in the eastern parts of Uzbekistan. Crop failures have deprived about 48,000 people of their main source of income and shortages of potable water have created a surge of infectious diseases.^{[needs update]}

Karakalpakstan is now mostly desert and is located in western Uzbekistan near the Aral Sea, in the lowest part of the Amu Darya basin. It has an area of 164,900 km² and is surrounded by desert. The Kyzyl Kum Desert is located to the east and the Karakum Desert is located to the south. A rocky plateau extends west to the Caspian Sea.

Its predecessor, the Karakalpak Autonomous Soviet Socialist Republic, was an autonomous republic in the Soviet Union until its incorporation into the Uzbek Soviet Socialist Republic in 1932. The Republic of Karakalpakstan maintained its predecessor's formal sovereignty, even after the independence of Uzbekistan in 1990. Karakalpakstan shares veto power with Uzbekistan over decisions concerning its affairs. According to the constitution, relations between Karakalpakstan and Uzbekistan are "regulated by treaties and agreements" and any disputes are "settled by way of reconciliation". Its right to secede is limited by the veto power of Uzbekistan's legislature over any decision to secede. Article 89, chapter XVII, Constitution of Uzbekistan, provides that: "The Republic of Karakalpakstan shall have the right to secede from the Republic of Uzbekistan on the basis of a nationwide referendum held by the people of Karakalpakstan."