556 (disambiguation)

556 is the year 556 AD.

556 may also refer to: 556 (number) 556 BC

5.56mm or 5.56×45mm NATO, a common rifle cartridge Sig 556, a commercial variant of the Sig SG 551 rifle designed for the American civilian market 5-56, a popular brand of penetrating oil 556 dual timer, an integrated circuit 556, a fictional character in the Sgt. Frog series