They Don't Know

They Don't Know may refer to:

• "They Don't Know" (Kirsty MacColl song), a 1979 song by Kirsty MacColl, covered in 1983 by Tracey Ullman
• "They Don't Know" (Jon B song), a 1998 song by Jon B
• They Don't Know (album), a 2001 album by So Solid Crew; also the name of its title song
• "They Don't Know" (Paul Wall song), a 2005 song by Paul Wall
• "They Don't Know" (Savage song), a 2006 song by Savage
• "They Don't Know", a song from the musical Thoroughly Modern Millie