Sintra is a town and municipality located on the Portuguese Riviera. The population of the municipality in 2011 was 377,835, in an area of 319.23 square kilometres (123.26 sq mi). Sintra is a major tourist destination in Portugal, famed for its picturesqueness and for its historic palaces and castles.

The area includes the Sintra-Cascais Nature Park through which the Sintra Mountains run. The historic center of the Vila de Sintra is famous for its 19th-century Romanticist architecture, historic estates and villas, gardens, and royal palaces and castles, which resulted in the classification of the town as a UNESCO World Heritage Site. Sintra's landmarks include the mediaeval Castle of the Moors, the romanticist Pena National Palace and the Portuguese Renaissance Sintra National Palace.

Sintra is one of the wealthiest and most expensive municipalities in both Portugal and the Iberian Peninsula as a whole. It is home to one of the largest foreign expat communities along the Portuguese Riviera and consistently ranks as one of the best places to live in Portugal.