To provide a caster and a leg base capable of suppressing forcible moving operation in a locked state, and further, smoothly performing operation of an operation member.

A caster 6 includes: a caster body 62; wheels 63 pivotally fixed to the caster body 62; and a brake mechanism 64 configured to lock the wheels 63 to the caster body 62 when operating an operation member 7 to a lower position and release the locked state when operating the operation member 7 to an upper position. The operation member 7 includes an upper operation piece 73 and a lower operation piece 74 arranged in a vertical direction at intervals. The lower operation piece 74 is close to a floor surface in an attitude standing with respect thereto in a lower position at which the wheels 63 are locked to the caster body 62.