General Brazilian
terra ocupada ilegalmente / invasão de terra
Most common usage in Brazil, frequently used in urban and rural contexts
Rio de Janeiro
favela / comunidade
Often refers to settlements in urban areas; terra ocupada is also used
São Paulo
ocupação / assentamento irregular
Common in discussions of land rights and social movements
Portugal
ocupação ilegal / ocupação abusiva
Less common phrase; Portuguese usage tends toward more formal legal terminology