Address Unknown may refer to:

• Address Unknown (novel), a 1938 short novel by Kathrine Taylor
• Address Unknown (1944 film), an American film based on Taylor's novel, directed by William Cameron Menzies
• Address Unknown (1986 film), an American film directed by John Gianvito
• Address Unknown (1997 film), an American film starring Kyle Howard
• Address Unknown (2001 film), a South Korean film directed by Kim Ki-duk
• "Address Unknown", a 1939 No. 1 hit song by The Ink Spots
• Address Unknown, a radio program written by Ross Napier
• Address Unknown, a fictional television show in the video games Max Payne and Max Payne 2