K–12 commonly refers to primary and secondary education in the United States and Canada.

K12 may also refer to:

• K–12 (album), by Melanie Martinez
  • K–12 (film), the accompanying film
• Sonata in A, K. 12, by Wolfgang Amadeus Mozart
• A fictional ski slope in the film Better Off Dead

• E. coli K-12, a bacterial strain
• Keratin 12, a protein
• Coxeter–Todd lattice K₁₂, a 12-dimensional lattice

• 21 cm K 12 (E) German World War II railway gun
• AMD K12, a CPU microarchitecture
• Curtiss K-12, an aircraft engine
• S&T Motiv K12, a South Korean machine gun
• K-12, an obsolete process for Kodachrome photographic film

• Kalinin K-12, a Soviet proof-of-concept aircraft
• Kawanishi K-12 Sakura, an experimental Japanese aircraft

• Kandi K12, a Chinese microcar
• Nissan Micra (K12), a Japanese subcompact car

• HMS Auricula (K12), a corvette of the Royal Navy
• HMS K12, a submarine of the Royal Navy
• HNLMS K XII, a submarine of the Royal Netherlands Navy
• HSwMS Malmö (K12), a corvette of the Swedish Navy

• K-12 (Kansas highway), a former highway in Kansas
• K12 (mountain)
• K12 Inc., now Stride, Inc., an American education company

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