The 59-year-old man’s visit to the Wetherill Park police station, where he was detained, prompted police to investigate.
Police said the woman had not been formally identified, but is believed to have been 62 years old and knew the man.
Officers captured the vehicle the man was driving to the police station and reported the crime scene to the home.
The man was taken to Fairfield Police Station, charged with murder and denied bail.
He is expected to appear before Fairfield local court on Tuesday.