The Malay world or Malay realm is a concept or an expression that has been used by different authors and groups over time to denote several different notions, derived from varied interpretations of 'Malay' either as an ethnic group, as a racial category, as a linguistic group or as a cultural group. The use of the term Malay in much of the conceptualisation is largely based on the prevalent Malay cultural influence, manifested in particular through the spread of the Malay language in Southeast Asia as observed by different colonial powers during the Age of Discovery and spread of Islam. The term remains highly controversial in Indonesia and outside the Malay-speaking areas, because it is considered politically charged and irredentist rather than purely cultural.

Malay is an Austronesian language that is an official language of Brunei, Indonesia, Malaysia, and Singapore, and that is also spoken in East Timor and parts of Thailand. Altogether, it is spoken by 290 million people across Maritime Southeast Asia.