From Packing.org
http://www.packing.org/state/index.jsp/georgia
Knife carry law summary:
Date updated: Wednesday, March 10, 2004
Georgia Code 16-11-126
(a) A person commits the offense of carrying a concealed weapon when such person knowingly has or carries about his or her person, unless in an open manner and fully exposed to view, any bludgeon, metal knuckles, firearm, knife designed for the purpose of offense and defense, or any other dangerous or deadly weapon or instrument of like character outside of his or her home or place of business, except as permitted under this Code section.
Georgia Code 16-11-127.1,
(a) As used in this Code section, the term:
(2) 'Weapon' means and includes any pistol, revolver, or any weapon designed or intended to propel a missile of any kind, or any dirk, bowie knife, switchblade knife, ballistic knife, any other knife having a blade of two or more inches,
Admin Note: Only under school carry is the length of a knife blade mentioned in Georgia Law. As 16-11-126 it looks like open carry of a knife is legal. More Information on Knife Carry can be found Here