As of 2001, the population of Cornubia was around 3,300. 10 years prior there were only 2,000 people in the area. The suburb has a young population (median age of 35). About 6% of people are unemployed. After English (90%), the most spoken languages are Dutch and German.
In the 2011 census, Cornubia recorded a population of 6,833 people, 49.9% female and 50.1% male. The median age of the Cornubia population was 37 years, the same as the national median. 70.2% of people living in Cornubia were born in Australia. The other top responses for country of birth were England 7%, New Zealand 6.4%, Scotland 1.7%, South Africa 1.5%, Germany 0.7%. 88.9% of people spoke only English at home; the next most common languages were 0.7% Mandarin, 0.6% Afrikaans, 0.5% German, 0.4% Dutch, 0.4% Greek.