K0 may refer to:

• Spectral class K0, a star spectral class
• the 1965 first modelgyfd of the Honda CB450 motorbike
• the Grothendieck group in abstract algebra
• the Lateral earth pressure at rest
• the neutral kaon, a strange meson with no charge in nuclear physics
• K₀ may refer to Khinchin's constant
• K₀ the order-zero graph

• All pages with titles containing k-0
• All pages with titles containing k0
• KO (disambiguation)