Monsters: The Lyle and Erik Menendez Story is the second season of the American biographical crime drama anthology television series Monster, created by Ryan Murphy and Ian Brennan for Netflix. The season centers on the 1989 murders of José (Javier Bardem) and Kitty Menendez (Chloë Sevigny), who were killed by their sons, Lyle (Nicholas Alexander Chavez) and Erik (Cooper Koch). It incorporates the Rashomon effect by presenting the story from multiple perspectives, with the brothers' viewpoint serving as the central narrative.

It is the second season in the Monster anthology series, following Dahmer – Monster: The Jeffrey Dahmer Story. Having initially ordered the program in 2020 as a limited series, Netflix announced in 2022 that it had been renewed as an anthology series, with two further editions based on the lives of "other monstrous figures." The second season, which focuses on the Menendez brothers, was announced to be in development on May 1, 2023.

Upon its premiere on September 19, 2024, the season received mixed reviews from critics, who praised the performances (particularly those of Bardem and Koch) but criticized its runtime, inconsistent tone, and the incestuous portrayal of the Menendez brothers. Erik Menendez denounced the season for its inaccuracies and the characterization of Lyle. It achieved global commercial success, debuting as the number-one series on Netflix worldwide. A third season, titled The Original Monster, is currently in development, starring Charlie Hunnam as serial killer Ed Gein.