A woman has died and a one-year-old girl is in a critical condition after they were pulled from a backyard pool in NSW's Illawarra region.

A police spokeswoman said the woman, a 50-year-old Korean national, died at the scene.

Paramedics were called to an address in Dapto, south of Wollongong about 2.30pm (AEDT) on Tuesday after reports the woman and the toddler had been pulled from the pool.

The girl was resuscitated and was at Wollongong Hospital waiting to be airlifted to Sydney, the spokeswoman said.

News Limited reported that the woman was the child's grandmother and is believed to have fallen into the pool while carrying the child during a family lunch at her daughter's home.

She reportedly suffered from a medical condition.