Nillumbik Shire's language statistics show the proportion of the overseas-born population who speak a language at home other than English. They indicate how linguistically diverse a population is, and whether most migrants are from English speaking countries or non-English speaking countries. This topic also shows those languages spoken specifically by the first-generation migrants (those born overseas) so as to separate them from those born in Australia who speak another language.

Some countries, such as India, have a variety of languages spoken there, so the language spoken can indicate the region of the country of origin. Languages such as Arabic and Spanish are spoken in a range of different countries.

Nillumbik Shire's language statistics should be analysed in conjunction with Proficiency in English to assist in identifying specific cultural and ethnic groups in the area and the services required by the multicultural community.