The Lost Cause of the Confederacy is a set of false beliefs about the American Civil War.

Lost Cause may also refer to:

• Lost Cause (Jandek album), 1992
• Lost Cause (Tory Lanez mixtape), 2014
• "Lost Cause" (Beck song), 2002
• "Lost Cause" (Billie Eilish song), 2021
• "Lost Cause", a 1983 song by Riot Squad
• "Lost Cause", a 1989 song by Cosmic Psychos
• "Lost Cause", a song by Priscilla Ahn from the album When You Grow Up (2011)
• "Lost Cause", a song by Pink from the album Trustfall (2023)
• "Lost Cause", a song by Dean Brody from the album Right Round Here (2023)
• The Lost Cause (novel), 2023 novel by Cory Doctorow
• Lost Cause Motors, an American automobile manufacturer from 1963 to 1964