Vác (Hungarian pronunciation: [ˈvaːts], Slovak: Vacov) is a town in Pest county in Hungary with approximately 35,000 inhabitants. The archaic spellings of the name are Vacz and Vacs.

Vác is located 35 kilometres north of Budapest on the eastern bank of the Danube river, below the bend where the river changes course and flows south. The town is seated at the foot of the Naszály Mountain in the foothills of the Carpathians.

Vác is a commercial center as well as a popular summer resort for citizens of Budapest. The cathedral, built 1761–1777, was modelled after St. Peter's Basilica in Rome. The episcopal palace houses a museum for Roman and medieval artifacts. The city is also known for its 18th century arch of triumph and for its beautiful baroque city center.

Settlement in Vác dating as far back as the Roman Empire has been found.

Bishops from the diocese were influential within the Kingdom of Hungary, with many serving as chancellors or later becoming archbishops.

The town was conquered by the Ottoman Empire in 1541. During the Habsburg Monarchy's wars against the Ottomans, the Austrians won victories against the Turks at Vác in 1597 and in 1684.