Praemonitus praemunitus or forewarned is forearmed may refer to:

• Motto of the United States Army Security Agency
• Motto of the U.S. Air Force Theater Battle Control Division at Hanscom Air Force Base, Massachusetts

• Praemonitus Praemunitus, the title of the second American edition of the Protocols of the Elders of Zion, first published in 1920
• Praemonitus Praemunitus, the motto of Investigations & Protective Services, Hollywood, Florida.
• Forewarned is Forearmed, the motto of the British Royal Observer Corps
• Praemonitus Praemunitus, the motto of the Gearing-class destroyer USS Forrest Royal
• Forewarned, Forearmed, the motto of the Australian Army Intelligence Corps.
• Forewarned, Forearmed, the motto of HMS Boxer.