San Sebastián town hall, Municipal building in La Concha Bay, Spain

San Sebastian Town Hall is an eclectically styled building located near the Alderdi Eder gardens facing the bay. The facade features classical ornamental details, and inside the space is divided into areas used for administrative work and public events.

The casino was designed by Adolfo Morales de los Ríos and Luis Aladrén Mendivil after a prize-winning competition, built between 1882 and 1887 and opened on 1 July 1887. At the start of the Civil War, rebels barricaded themselves inside and were dislodged by militiamen after hard fighting; bullet marks remain on the facade facing the Boulevard. The concession returned to the municipality, and after alterations by the architects Aldai and Arizmendi the building opened as the town hall on 20 January 1947.

The building opened on 1 July 1887 as the Gran Casino, and Queen Maria Christina of Austria attended its inauguration. From 1887 to 1924 it operated as a casino in the Alderdi Eder gardens, near the yacht club. In 1928 a tourism office opened in the building before later moving to the nearby Hotel María Cristina.

The building stands in the Alderdi Eder gardens, between the Old Town, the port and the Club Náutico, facing the bay of La Concha. The facade on the Boulevard side still shows bullet marks from the Civil War fighting. The former town hall on Constitution Square in the Old Town now houses the municipal library.

The building opened as the Gran Casino on 1 July 1887, with Queen María Cristina of Austria attending the inauguration. It operated as a casino until 1924, when the municipal concession reverted; from 1937 the city negotiated with the Sociedad de Fomento, then chaired by Luis Gaytán de Ayala, to convert it. Architects Aldai and Arizmendi revised the first plans in 1943.