A good Samaritan has been stabbed to death trying to stop a domestic dispute in his neighbour’s house in western Sydney.

The 50-year-old man died at the scene after he was stabbed a number of times at the home in Waikanda Crescent, Whalan, about 5.30pm on Saturday.

A 19-year-old man was allegedly fighting with people known to him, including his mother, when the good Samaritan intervened and was fatally stabbed, a police spokesman told AAP.

The 19-year-old has been charged with murder and is expected to appear at Parramatta Bail Court on Sunday.

A woman and child in the townhouse were not injured.