The victim was identified as 19-year-old Oshiana Tompkins and the other victims were identified by police as Tiyon Farley, 22, Omar Taylor, 24, Ramon Hill Jr., 23, and Javin County, 29, KGO-TV reported.
Gunfire erupted around 11 p.m. during the party at an Airbnb in Orinda, Calif, east of San Francisco.
When police arrived, they found three gunshot victims who were pronounced dead on arrival. A fourth victim was transported to an area hospital where he later died.
Neighbors told KGO there have been other wild parties at the Airbnb before and there were at least two noise complaints about the party before the shooting.
The owner said she was told the home was being rented for a small family reunion.
In Orinda, Short term rentals are limited to 13 people.