K9

K9 or K-9 may refer to:

Homophone for canine

• Canine (disambiguation)
• Dog, the domestic dog
  • Assistance dog
  • Guard dog
  • Police dog

Fictional dogs

• K9 (Doctor Who), several robotic canines in the British science fiction television series Doctor Who
• K-9 (Looney Tunes), Marvin the Martian's pet Martian dog in the Looney Tunes cartoon series from Warner Bros
• K-9 (Transformers)
• K9 Murphy, a mechanical dog in the Japanese television series Tokusou Sentai Dekaranger

Computing

• AMD K9, a microprocessor
• K9Copy, a DVD backup and authoring program for Unix-like operating systems
• K-9 Mail, a mail client for the Android operating system
• K9 Web Protection, Web content control software

Entertainment

• K-9 (film), starring James Belushi
• K-9 (TV series) a British/Australian comedy/adventure series starring the same character as featured in Doctor Who
• KNIN-TV, a television station for Idaho's Treasure Valley, previously known as K9
• Violin Sonata No. 4 (Mozart) K. 9, by Wolfgang Amadeus Mozart

Military and weapons

• HMAS K9, an Australian submarine
• Pusan East (K-9) Air Base, an abandoned air base in Busan, South Korea
• K9 Thunder, a 155 mm self-propelled artillery used by the Republic of Korea Armed Forces
• Kahr K9, a 9×19mm Parabellum semi-automatic pistol manufactured by the American company Kahr Arms
• K-9 (missile), a Soviet short-range air-to-air missile

Other

• Kia K9, a car
• K-9 (Kansas highway), a state highway in the U.S. state of Kansas
• BYD electric bus, called K9 in China
• K9, a children's shoe size