Inclement weather held off for most of the day as people from throughout the Highlands descended on the village for the region's annual Australia Day festivities.

Official proceedings began at 9.30am as Berrima Historic Court House marked by a citizenship ceremony as well as words from Wingecarribee Australia Day ambassador Alan Terrell.

Mr Terrell, a Berrima resident, was an aviation pioneer and settled in the Highlands before making his mark on the community through his involvement with Harper's Mansion and his role as chair of Berrima Court House Trust.

The 83-year-old spoke of becoming an Australian citizen in the 1940s and the importance of recognising Australia's Indigenous heritage.

Ten Highlands residents were officially sworn in as Australian citizens, something which Deputy Mayor Larry Whipper said was even more significant on Australia Day.

"You don't turn your back on your country of origin and your culture, but you share them," he said.

Despite the absence of the Southern Highlands Concert Band due to the threat of rain, singer Nina D'Arcy soldiered on and gave stirring acapella performances of I Love A Sun Burnt Country and We Are Australian.

Cr Juliet Arkwright said Ms D'Arcy's ability to improvise and go with the flow reflected the Australian spirit.

Wingecarribee Citizen of the Year was awarded to volunteer Jennifer Bowe while Brittany McCrea was named Young Citizen of the Year.

Ms Bowe said it was a great but unexpected honour to be recognised in front of the community.

Ms Bowe is known in the region as a hard-working volunteer and lends her services in her spare time to the Country Women's Association, Friends of the Wingecarribee Library, International Cricket Hall of Fame and Volunteering Wingecarribee.

She has also been involved in community initiatives such as Southern Highlands Domestic Violence Forum and International Women's Day.

"I was shocked when I was nominated," she said.

Noon drew hundreds of people to the edges of the Old Hume Highway, where the annual parade passed by.

Vintage cars, fire engines, ambulances and marching musicians proceeded through the middle of town among a sea of miniature Australian flags.

The parade finished at Market Place Park, where families and friends spent the afternoon enjoying market stalls, food and Australian music.