1. Military

2. Music

3. Books

4. Television

Blue on blue may refer to:

Military

• Friendly fire (inadvertent firing toward friendly forces), called "blue on blue" in NATO terminology

Music

• "Blue on Blue" (song) a 1963 hit song recorded by Bobby Vinton
  • Blue on Blue (Bobby Vinton album), 1963
• Blue on Blue (Leigh Nash album), 2006
• "Blue on Blue", a song by James Blunt from Moon Landing
• "Blue on Blue", a song by the Pet Shop Boys on the "Minimal" DVD

Books

• An Insider's Story of Good Cops Catching Bad Cops, 2017

Television

• "Blue on Blue" (Ugly Betty), an episode of Ugly Betty
• "Blue on Blue" (Under the Dome), an episode of Under the Dome

• 9th Reconnaissance Technical Squadron
• 9th Regiment Illinois Volunteer Cavalry
• 9th Regiment Iowa Volunteer Cavalry
• 9th Regiment Kansas Volunteer Cavalry
• 9th Regiment Maryland Volunteer Infantry
• 9th Regiment of Lesser Poland Uhlans
• 9th Reserve Battalion, CEF
• 9th Reserve Division (People's Republic of China)
• 9th Rifle Corps
• 9th Saturn Awards
• 9th Shorty Awards
• 9th Space Operations Squadron
• 9th Squadron (Iraq)
• 9th Squadron (JASDF)
• 9th Sri Lankan Parliament
• 9th SS Police Regiment
• 9th Street (Charlotte Trolley station)
• 9th Street-Congress Street (HBLR station)
• 9th Street-Congress Street station
• 9th Street-Congress Street station (Hudson-Bergen Light Rail)
• 9th Street Expressway
• 9th Street (PATH station)
• 9th Street (Pulse station)
• 9th Street (SEPTA station)
• 9th Street station