Making a Murderer is an American true crime documentary television series written and directed by Laura Ricciardi and Moira Demos. The show tells the story of Steven Avery, a man from Manitowoc County, Wisconsin, who served 18 years in prison (1985–2003) after his wrongful conviction for the sexual assault and attempted murder of Penny Beerntsen. He was later charged with and convicted of the 2005 murder of Teresa Halbach. The connected story is that of Avery's nephew Brendan Dassey, who was accused and convicted as an accessory in the murder of Halbach.

The first season mainly chronicles the period between 1985 and 2007, portraying Avery's 1985 arrest and conviction, his subsequent exoneration and release in 2003, the civil lawsuit Avery filed against Manitowoc County, his 2005 arrest, and his ensuing trial and conviction in 2007. It also depicts the arrest, prosecution, and conviction of Dassey, focusing on the accusations of coercion and attorney ineptitude.

The second season explores the aftermath of both Avery's and Dassey's convictions, focusing on Avery's and Dassey's families, the investigation and findings of Avery's new attorney Kathleen Zellner, which supported the thesis of Avery's innocence and him being framed for the murder of Halbach, and Dassey's legal team's efforts in arguing that his confession was coerced by prosecutors and his constitutional rights were violated.

The first season premiered on Netflix on December 18, 2015. It was filmed over the course of 10 years, with the filmmakers moving back and forth from New York City to Wisconsin during filming. To promote the series, Netflix released the first episode concurrently on YouTube and on Netflix, which it had not done for any other original programming.

In July 2016, Netflix announced the second season, to explore the aftermath of Dassey's conviction and the numerous appeals that had taken place. The 10-episode second season was released on October 19, 2018.

Making a Murderer won several awards, including four Primetime Emmy Awards in 2016. As a production, the series was favorably compared to the HBO series The Jinx and the podcast Serial. Making a Murderer was widely viewed and has generated considerable controversy, both in Manitowoc County, the setting of events, and nationwide. A petition in December 2015 to the White House to pardon Avery garnered more than 500,000 signatures. The White House's statement noted "the President cannot pardon a state criminal offense."