Grand Theft Auto IV: The Lost and Damned is the first of two planned episodic expansion packs to be developed for the Xbox 360 version of the sandbox-style action-adventure video game Grand Theft Auto IV, developed by Rockstar North. The first episodic pack was released on Xbox Live on 17 February 2009.

The Lost and Damned features a new protagonist, Johnny Klebitz, who is a member of Liberty City's biker gang The Lost, a gang which is featured in several missions throughout the course of Grand Theft Auto IV. Dan Houser, vice president of creative development at Rockstar Games, claims the episode will show "a different side of Liberty City" Jeronimo Barrera, Vice President of Product Development for Rockstar Games, has said that the episodes are experiments because they are not sure that there are enough users with access to online content on the Xbox 360. Take-Two Interactive's Chief Financial Officer, Lainie Goldstein revealed that Microsoft was paying a total of $50 million for the first two episodes.

The content was first announced during Microsoft's 2006 E3 press conference on 9 May 2006. Peter Moore, the then-head of Microsoft's Interactive Entertainment Business division described downloadable content as "epic episode packs", and not just an extra car or character. A press release during the conference said that the packs would add "hours of entirely new gameplay" to the game.[8] On 20 February 2008, it was initially announced that the extra content would be introduced starting August 2008. As part of its second quarter financial reports Take-Two announced that the downloadable content had been delayed and would be released during the first quarter of its 2009 financial year (November 2008–January 2009). On 13 November 2008, Take-Two executive chairman Strauss Zelnick warned that while they were aiming to release the first episode pack by January 2009, the date may have had to change to the second financial quarter of 2009 (February-April) depending on the completion date. The 17 February release date was eventually announced one week after Zelnick's warning.