The Royal Institute of British Architects Stirling Prize is a British prize for excellence in architecture. It is named after the architect James Stirling, organised and awarded annually by the Royal Institute of British Architects (RIBA). The Stirling Prize is presented to "the architects of the building that has made the greatest contribution to the evolution of architecture in the past year". The architects must be RIBA members. Until 2014, the building could have been anywhere in the European Union, but since 2015 entries have had to be in the United Kingdom. In the past, the award included a £20,000 prize, but it currently carries no prize money.

Sir James Frazer Stirling was a British architect.