Jászberény is a city and market centre in Jász-Nagykun-Szolnok county in Hungary.

Jász–Nagykun–Szolnok is an administrative county in Hungary. It lies in central Hungary and shares borders with the Hungarian counties Pest, Heves, Borsod–Abaúj–Zemplén, Hajdú–Bihar, Békés, Csongrád, and Bács–Kiskun. The rivers Tisza and Körös flow through the county. The capital of Jász–Nagykun–Szolnok county is Szolnok. Its area is 5582 km2. The county is named after the Ossetians (Jasz) and Cumans (Kun) who settled there, along with Szolnok. The county was part of the Danube–Criș–Mureș–Tisa Euroregion between 1997 and 2004.