Nové Zámky (in German: Neuhäusl or Neuhäusel, in Hungarian: Érsekújvár, in Turkish: Uyvar) is a town in southwestern Slovakia. Seat of a district (okres).

The town is best known because of its famous history. An anti-Turkish fortress has been built on the site of an older settlement in the years 1573-81. Today's town arose around the fortress. The huge new fortress was one of the most modern fortresses in Europe when it was built. The Turks failed to conquer it six times, but in 1663 they managed to do so and made it the center of a Turkish province in southern Slovakia. In 1685 it has been conquered by imperial troops of Charles of Lorraine.

It also played an important role in many Anti-Habsburg uprisings in the 17th century in Slovakia. The emperor had it razed in 1724-1725 to prevent potential further insurrections which would use the fortress as their base. Finally, during World War II (1944), the town was heavily damaged by bombings of the Allies. Only small parts of the fortress still exist today.