SYDNEY—A resources boom and growing immigration from Asia are reshaping Australia's population.

Mandarin overtook Italian as the second most popular language spoken at home, after English, figures from the 2011 census published Thursday showed.

Data from the Australian Bureau of Statistics showed that the resource-rich regions of Western Australia and Queensland both recorded double-digit population growth over the past five years, more than double that of Australia's most populous state, New South Wales, and sharply outstripping the national average of 8.3%.

Asians accounted for the biggest jump in immigration to Australia in terms of ethnicity, with Indian and Chinese the fastest-growing groups. The census showed that around one in four of the 21.5 million people surveyed in the census last year was born outside Australia, compared with 22% a decade ago. Of those, a third was born in Asia, a sharp increase from 24% in 2006.

Meanwhile, the proportion of European migrants has fallen from more than half of arrivals a decade ago to 40% last year. The U.K. remains the leading country of origin for Australia's overseas-born population at 21%, including more than a quarter of long-standing migrants.