Major police search finds missing 8-year-old girl

An eight-year-old autistic girl missing in Sydney's south west this morning has been found after a major police operation.

Wendy Nguyen will be checked by paramedics before being reunited with her family, police said in a statement.

Her parents reportedly raised the alarm at 7am after waking to find their daughter was not in her bed.

She was last seen walking along Bishop Crescent at Bonnyrigg and heading towards Humphries Road about 5.30am, police said.

Fairfield local area commander Superintendent Peter Lennon said police were relieved Wendy had been found safe and well.

"We would like to thank local businesses, members of the public and the media for their assistance," he said.