Bács-Kiskun is a county located in southern Hungary. It was created by the merger of the pre-World War II Bács-Bodrog and the southern parts of Pest-Pilis-Solt-Kiskun counties. With an area of 8,445 km2, Bács-Kiskun is the largest county in the country, slightly larger than Cyprus. The terrain is mostly flat with slight emergences around Baja. The county seat and largest city of Bács-Kiskun is Kecskemét.

Pest-Pilis-Solt-Kiskun is the name of an administrative county (comitatus) of the Kingdom of Hungary. Its territory is now in central Hungary, comprising roughly the territory of the present Hungarian county Pest and the northern part of present Bács-Kiskun county. The capital of the county was Budapest.