The 55-year-old woman was around 20 metres from the short at Little Congwong Beach at La Perouse when she was bitten by what she described as a shark about 7pm.

After being helped to shore, she was treated by paramedics for lacerations to her leg and was taken to St George Hospital in a stable condition.

According to SharkSmart, a NSW Department of Primary Industries shark biologist assessed pictures of the woman’s injuries and has determined it was most likely a great white shark responsible for the attack.

Randwick mayor Lindsauy Shurey said the community was in shock after the attack, which has closed all La Perouse beaches for at least 24 hours.

“From all accounts the woman was very lucky and certainly the whole community's heartfelt thoughts are with her for a full recovery,” she said.

“I’ve lived in the area for 25 years and this is the first confirmed shark attack in Randwick City. We’re all a little shocked and concerned.

“Council lifeguards will be stationed at the usually unpatrolled beaches on Saturday to advise swimmers not to swim.”