Paldiski is a town and Baltic Sea port situated on the Pakri peninsula of north-western Estonia. Originally a Swedish settlement known as Rågervik, it became a Russian naval base in the 18th century. The Russians renamed it Балтийский Порт ("Baltiyskiy Port", i.e. Baltic Port, German: Baltisch-Port) in 1762. In Estonian the name was spelled Baltiski until 1933 when the Estonian pronunciation Paldiski became the official name.

In 1962, Paldiski became a Soviet Navy nuclear submarine training centre. With two land-based nuclear reactors, and employing some 16,000 people, it was the largest such facility in the Soviet Union. Because of its importance, the whole city was closed off with barbed wire until the last Russian warship left in August 1994. Russia finally relinquished control of the nuclear reactor facilities in September 1995.

After Estonia restored its independence, the city had not enough Estonian citizens and Paldiski was subordinated to Keila until 30 October 1996. Located some 45 km west of Tallinn, Paldiski is a municipality within Harju County and has a regular ferry connection with Kapellskär in Sweden (operated by Tallink). Derelict Soviet-style apartment buildings make up much of the town, and the relics of military bases are widespread. The majority of its residents are ethnic Russians.