Many metropolitan cities have undergone rapid demographic changes in recent years, and such changes hasten and widen linguistic diversities. Similar changes are happening in Sydney, Australia and Hamburg, Germany. These changes are most acutely felt and observed in the classrooms where multiple languages are spoken, despite a prevalent monolingual mindset in education in both these contexts. What do pre-service teachers think of language learning and multilingualism in the face of demographic and sociolinguistic changes? This is a particularly urgent question for pre-service teachers, whose perspectives on multilingualism will considerably influence on how their students view language learning and maintenance. Based on a survey of 436 pre-service teachers in Sydney and Hamburg, this comparative study explores the relationship between their linguistic profiles (monolingual, multilingual and how they become multilinguals) and the way they perceive societal multilingualism and the need to promote multilingual education to all. The findings suggest that formal language education, more than heritage backgrounds and knowledge, provided the necessary experience to foster a more open attitude towards societal multilingualism and language learning.