Lake Tisza, also known as Kiskörei-víztározó (Kisköre Reservoir), is the largest artificial lake in Hungary.
It is located at the southeastern edge of Heves county, next to counties Borsod-Abaúj-Zemplén, Hajdú-Bihar and Jász-Nagykun-Szolnok. As part of the ongoing Tisza River flood control project, the Tisza Dam was built in 1973. Its filling was finished in the 1990s, resulting a 127 km² lake. The lake is 27 km in length, with an average depth of 1.3 m and a maximum depth of 17 m; it contains 43 km² of small islands.