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), the fifth episode, cinematography, and score but criticized its runtime, inconsistent tone, and overtly sexualized approach. It was denounced by Erik Menendez and his relatives for its inaccuracies and Lyle's portrayal, and it further garnered controversy for implying an incestuous relationship between the Menendez brothers. It achieved global commercial success, debuting as the number-one series on Netflix worldwide and the most-viewed streaming content on the Nielsen Streaming Chart. At the 82nd Golden Globe Awards, the season earned three nominations: Best Limited or Anthology Series or Television Film, Best Actor – Miniseries or Television Film for Koch, and Best Supporting Actor – Series, Miniseries or Television Film for Bardem.

A third season, titled The Original Monster, is currently in production, starring Charlie Hunnam as murderer and graverobber Ed Gein.