Abstract: A leveling jack for a gun sight (or ‘scope’) of a gun or rifle is provided. The leveling jack is movable between at least a first and a second position and is secured to a gun or rifle. The leveling jack has a bottom edge which may be secured to, for example, the picatinny rail of the top of the gun or rifle and an extended bar which contacts and levels the gun sight. The leveling jack may also be secured directly to the gun or rifle without utilizing a picatinny rail. The leveling jack is especially suitable for leveling the gun sight of the gun or rifle in a quick and efficient manner.