Firefighters and paramedics were sent to a party where the shooting was reported in the 3300 block of East 14th Street about 12:30 a.m. Sunday, according to the Los Angeles Fire Department.
Randy Tyson, 25, and Daniel Dunbar, 27, both of Los Angeles, died at the scene, the Los Angeles County coroner's office reported.
Another man died at a hospital, according to the Los Angeles Police Department. Information on his identity was not immediately available.
One person was hospitalized in critical condition, two others were hospitalized in stable condition, and a fourth was treated and released, the LAPD reported.
The shooting took place at a party that featured a performance by the Huntington Park rapper Money Sign Suede.
"Just wanna get on here real quick to send my condolences to what happened after this paid show yesterday," the rapper wrote in an Instagram post. "I pray for all the people who were injured and died last night."
No arrests were reported.
Anyone with information on the case was urged to call (877) LAPD-247.
City News Service contributed to this report.