Thousands of Sydneysiders are leaving their home suburbs for other parts of the city and the state with new figures revealing a slowdown in the capital's runaway population growth.

Australian Bureau of Statistics data showed the Greater Sydney area added 93,411 residents through 2017-18, taking the city's total population to a record 5.2 million. It was the smallest increase in the population since 2014-15.

Greater Sydney added 93,411 residents in 2017-18. Credit:Wolter Peeters

It was driven by net overseas migration which added 71,000 residents to the city over the year, offsetting a 27,300 loss from existing Sydneysiders who moved to another part of the country. The rest of the increase was made up by natural increases.

But the overseas and internal migration numbers hid big changes in different parts of the city.