The Daman and Diu Portuguese or Daman and Diu Indo-Portuguese, known to its speakers as Língua da Casa (Portuguese for "Home language"), is a Portuguese-based creole spoken in Daman and Diu. Before the Indian annexation of the territory, the Daman creole went through a profound decreolization by Standard Portuguese of Goa, a phenomenon whereby the Indo-Portuguese creole reconverged with Standard Portuguese.
The Daman creole is a descendant of the Norteiro creole, spoken originally by the Norteiros on the Coast from Chaul, Baçaim, Bombay, Daman and Diu.
The superstrate language is Portuguese. The substrate of the Daman creole is likely to be Konkani. Gujarati has also been suggested as a possible substrate, but this is doubtful, since the Gujarati people moved into the region only after the Portuguese arrived.
The Diu Indo-Portuguese or Diu Portuguese is spoken in Diu, India. It is a creole language based mainly on Portuguese and Gujarati. It is a member of the larger family of Indo-Portuguese creoles, particularly close to the variety of Daman. There is a considerably vital oral tradition in this language, with songs regularly performed in Diu, elsewhere in India and among Indo-Portuguese communities abroad.
The Indo-Portuguese creoles are the several creole languages of India and Sri Lanka which had a substantial Portuguese influence in grammar or lexicon, such as
The expression Indo-Portuguese may refer not only to the creoles but also to the ethnic groups speaking those languages.