Cascais (Portuguese pronunciation: [kɐʃˈkajʃ] (listen)) is a municipality in the Lisbon District of Portugal, located on the Portuguese Riviera. The population in 2011 was 206,479, in an area of 97.40 km2. Cascais is an important tourist destination. Its marina hosts events such as the America's Cup and the town of Estoril, part of the Cascais municipality, hosts conferences such as the Horasis Global Meeting.
Cascais's history as a popular seaside resort originated in the 1870s, when King Luís I of Portugal and the Portuguese royal family made the seaside town their residence every September, thus also attracting members of the Portuguese nobility, who established a summer community there. Cascais is known for the many members of royalty who have lived there, including King Edward VIII of the United Kingdom, King Juan Carlos I of Spain, and King Umberto II of Italy. Exiled Cuban president Fulgencio Batista was also once a resident of the municipality. The Casino Estoril inspired Ian Fleming's first James Bond novel Casino Royale.
The municipality is one of the wealthiest in both Portugal and the Iberian Peninsula. It has one of the most expensive real estate markets and one of the highest costs of living in the country and is consistently ranked highly for its quality of life.