Clandestine may refer to secrecy or to:

• Clandestine Systems, Defense Contractor Laser Displays
• Clandestine Industries, a clothing line by Fall Out Boy's Pete Wentz
• Clandestine operation, a secret military or political activity
• National Clandestine Service, formerly the CIA's Directorate of Operations
• Clandestine chemistry, chemistry carried out in secret
• Clandestinity (canon law), an impediment to marriage in the canon law of the Roman Catholic Church
• Clandestine (novel), a novel by James Ellroy
• Clandestine (album), an album by Entombed
• Clandestine MUD, a MUD, or text-based MMORPG
• Clandestine, a short film by the band AFI, featured on the special edition of the album Sing the Sorrow
• Clandestine (band), a Celtic music band from Houston, Texas
• Clan Destine, a comic book series by Alan Davis and published by Marvel Comics about a family of British superheroes in the Marvel Universe
• Clandestino, an album by Manu Chao
• La Clandestine Absinthe, an absinthe distilled in Switzerland
• Clandestiny, an adventure game
• Clandestine Insurgent Rebel Clown Army (CIRCA), an antimilitarist British action group of clowns dressed in army uniforms
• Organisation Clandestine, an underground Electro and House Music organisation in Melbourne

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