Azulejo (Spanish: [aθuˈlexo], Portuguese: [ɐzuˈleʒu, ɐzuˈlɐjʒu]; from the Arabic al-zillīj, الزليج) is a form of Spanish and Portuguese painted tin-glazed ceramic tilework. Azulejos are found on the interior and exterior of churches, palaces, ordinary houses, schools, and nowadays, restaurants, bars and even railways or subway stations. They are an ornamental art form, but also had a specific functional capacity like temperature control in homes.

There is also a tradition of their production in former Spanish and Portuguese colonies in North America, South America, the Philippines, Goa (India), Lusophone Africa, East Timor, and Macau (China). Azulejos constitute a major aspect of Spanish architecture and Portuguese architecture to this day and are fixtures of buildings across Spain and Portugal and its former territories. Many azulejos chronicle major historical and cultural aspects of Spanish and Portuguese history.