Country of Birth data identifies where people were born and is indicative of the level of cultural diversity at the chosen age group in Mosman Municipal Council. The mix of Country of Birth groups in different age groups is also indicative of historical settlement patterns, as source countries for Australia's immigration program have varied significantly over time. Typically, older populations are more likely to have been born overseas, however the countries of birth are different to the young, with migration from Europe dominating among those over 60, while Asian countries such as China and India are more common birthplaces among the young.

Mosman Municipal Council's Country of Birth data should be viewed together with Language Spoken at Home data and data specific to the characteristics of the birthplace or people born overseas in total.