Authorities are urgently searching for Joelene Brindle, a 32-year-old mother, and her 14-month-old son, Ma-Thayus Thomas, who went missing from the NSW south coast.

Joelene Brindle is described as an Aboriginal/Torres Strait Islander woman, approximately 170 cm tall with a thin build, long black hair usually tied in a high bun with a white bow, and was last seen wearing a white shirt and green shorts.

Her son, Ma-Thayus, is described as an Aboriginal/Torres Strait Islander boy, about 75 cm tall with a medium build, short brown hair, and brown eyes.

They were last seen on Sophia Street in Shellharbour around 7 pm on Wednesday, prompting police to notify the public after their disappearance.

Authorities believe the mother and child are traveling together and may be in Sydney's eastern suburbs, specifically in Maroubra or Little Bay.

Police are urging anyone with information about their whereabouts to contact Shellharbour Police or Crime Stoppers to assist in their safe recovery.