The oldest traces known to date of man's presence in the area of Sopot. Flint tools from the later Stone Age found in the second half of the 20th century in Zoppot.

In 1819 the first attempts were made to set up a bathing-site in Sopot, inspired by the existence since 1808 of a similar site in the neighbouring Brösen. On the site of today's Grand Hotel Karol Krzysztof Wegner, the owner of the biggest fortune in Sopot, built a modest, wooden bath-house with two baths and a boiler for warming the sea-water, as well as a wooden changing-room for those bathing in thesea. In the following year this establishment served 87 health-seekers, and after two years of activity, 167.

Jan Jerzy Haffner from Colmar, a former doctor in the Napoleonic Army, who had settled in Gdańsk in 1808, built in 1823 the first brick building of a hot baths complex with 6 baths and he also laid out the Królewskie Planty [Royal Park] around this building. All of this was on land on the sea-shore obtained from the Prussian Treasury. By the mouth of the Potok Elizy [Eliza Stream], now called the Potok Haffnera [Haffner Stream], he constructed wooden changing-rooms for ladies bathing in the sea, while near the mouth of the Potok Kuzniczy [Forge Stream], similar changing-rooms for gentlemen were built.

The Kaiser's decree of 8 October 1901 begins the procedure of transforming the administration into urban structures.

The opening of the new Warm Baths (Warmbad) had place in 1904. Three years later building of the new Southern Bath-house was open.

Building of the new Cure House (Kurhaus) with a theatre, dancing room, restaurants, reading-room, wine-bar, hotel rooms and observation terraces was rebuilt between 1910 - 1912. The pier is extended to 315 metres.

In 1920, as part of the settlement of the Versailles Treaty Sopot becomes part of the Freie Stadt Danzig, as a separate district.