Cathedral of the Sea () is a 2006 historical novel by Spanish author Ildefonso Falcones. The action takes place in 14th century Barcelona at the height of the city's trade and military power in the Mediterranean, during the construction of Santa Maria del Mar serving as background to the story.
In 2018, a high-budget drama series adaptation by Atresmedia was broadcast in Antena 3 from 23 May 2018 to 18 July 2018. Netflix released the series worldwide in 1 September 2018.
The book is set in Barcelona and its main character is Arnau Estanyol, son of a fugitive serf, who is one of the cathedral's stone workers, then obtains freedom, eventually achieving high status in society.
The novel has won several literary awards including: