It is the southernmost county, and its capital is the city of Alytus.

Its territory lies within the ethnographic region of Dzūkija.

On 1 July 2010, the county administration was abolished,[3] and since that date, Alytus County remains as the territorial and statistical unit.

It borders the Vilnius County in the east, Marijampolė County and Kaunas County in the north, Podlaskie Voivodeship of Poland in the west, and Grodno Region of Belarus in the south.

Alytus County has 5 constituent municipalities: The town of Druskininkai, a spa visited for its healing waters, is located in Alytus County, as is Grūtas Park, also known as Stalin World, a Soviet theme park.