The latest domestic visitor estimates for the Southern Highlands have been released from Tourism Research Australia's National Visitor Survey.

Removing the one-off impact of the Olympics, domestic overnight visitor numbers are the highest for any calendar year since records began in 1998.

Destination Southern Highlands manager Steve Rosa said domestic overnight visitors to the Wingecarribee Shire fell just short of the 450,000 mark for the year ending December 2014.

"The last time we saw this volume was in the year 2000," he said.

Mr Rosa said while visitor numbers were a good indication of how the Highlands was perceived as a destination, the number of nights the visitors stayed was what made a significant difference to the economy.

The number of nights spent in the Wingecarribee Shire in 2014 by domestic visitors was 1.1 million, the highest since 2000.

There were also more than one million domestic day visitors in 2014, for only the third time since 1998.

Mr Rosa said often one figure would rise while the other falls, so to have both on the rise was a benefit to the region, and also unique to the Highlands.

"We're not simply 'riding the same wave' that everyone else is" he said.

"Our growth is well above that of the surrounding capital country region and even further above regional NSW.

"Visitor nights to the region grew 24 per cent in 2014 and for regional NSW growth was only one per cent.

"Our nights growth was double that of the Region and completely against the grain when you look at Regional NSW as a whole," Mr Rosa said.

Expenditure data for the Southern Highlands recently released by Tourism Research Australia puts the domestic expenditure for 2014 just over $250 million into the Wingecarribee Shire visitor economy.