Joseph Lyle Menendez (born January 10, 1968) and Erik Galen Menendez (born November 27, 1970), collectively referred to as the Menendez brothers, are American brothers and convicted murderers who killed their parents, José and Mary Louise "Kitty" Menendez, at their Beverly Hills home in 1989.

Following the murders, Lyle and Erik claimed that unknown intruders were responsible for the murders, framing it as a potential mob killing. Police initially investigated this claim, but grew suspicious of the brothers' lavish spending of their multimillion-dollar inheritance, and their hiring of a computer expert to delete their father's recently updated will. Erik later confessed to the murders during a recorded session with his psychologist, which led to their arrests months later.

Lyle and Erik were charged with two counts of first-degree murder with special circumstances for lying in wait, making them eligible for the death penalty, and charges of conspiracy to murder. During their first trial, the defense argued that the brothers killed their parents in self-defense after years of alleged sexual, emotional, and physical abuse. The prosecution argued that the murders were premeditated, that allegations of sexual abuse were fabricated, and that the brothers were motivated by hatred and a desire to receive their father's multimillion-dollar estate after being disinherited from his will. The juries were unable to reach a verdict, resulting in mistrials for both brothers. In a second trial, they were convicted of first-degree murder and sentenced to life imprisonment without the possibility of parole.

Lyle and Erik currently serve life sentences at the Richard J. Donovan Correctional Facility in San Diego, California. Multiple legal appeals of their convictions have been rejected by reviewing judges. In October 2024, Los Angeles district attorney George Gascón recommended a resentencing after reviewing a habeas corpus petition.

The highly publicized trials received international media attention, inspiring numerous documentaries, dramatizations, books, and parodies.