Karnataka (; ISO: Karnāṭaka, Kannada pronunciation: [kɐˈɾnäːʈɐkɐ], also known as Karunāḍu), formerly Mysore State , is a state in the southwestern region of India. It was formed as Mysore State on 1 November 1956, with the passage of the States Reorganisation Act and renamed Karnataka in 1973. The state corresponds to the Carnatic region. Its capital and largest city is Bengaluru.

Karnataka is bordered by the Lakshadweep Sea to the west, Goa to the northwest, Maharashtra to the north, Telangana to the northeast, Andhra Pradesh to the east, Tamil Nadu to the southeast, and Kerala to the southwest. It is the only southern state to have land borders with all of the other four southern Indian sister states. The state covers an area of 191,791 km² (74,051 sq mi), or 5.83 percent of the total geographical area of India. It is the sixth-largest Indian state by area. With 61,130,704 inhabitants at the 2011 census, Karnataka is the eighth-largest state by population, comprising 31 districts. Kannada, one of the classical languages of India, is the most widely spoken and official language of the state. Other minority languages spoken include Urdu, Konkani, Marathi, Tulu, Tamil, Telugu, Malayalam, Kodava and Beary. Karnataka also contains some of the only villages in India where Sanskrit is primarily spoken.

Though several etymologies have been suggested for the name Karnataka, the generally accepted one is that Karnataka is derived from the Kannada words karu and nādu, meaning "elevated land". Karu Nadu may also be read as karu, meaning "black" and nadu, meaning "region", as a reference to the black cotton soil found in the Bayalu Seeme region of the state. The British used the word Carnatic, sometimes Karnatak, to describe both sides of peninsular India, south of the Krishna.

With an antiquity that dates to the paleolithic, Karnataka has been home to some of the most powerful empires of ancient and medieval India. The philosophers and musical bards patronised by these empires launched socio-religious and literary movements which have endured to the present day. Karnataka has contributed significantly to both forms of Indian classical music, the Carnatic and Hindustani traditions.

The economy of Karnataka is the fifth-largest of any Indian state with ₹20.5 trillion (US$260 billion) in gross domestic product and a per capita GDP of ₹305,000 (US$3,800). Karnataka has the fifteenth-highest ranking among Indian states in Human Development Index.