A feline litter box sieve system includes a screened lid connected by a hinge to a support frame that suspends an empty litter box in the top opening of a trash receptacle. L-shaped hooks suspend the support frame in the trash receptacle. Used litter is poured from a full litter box onto the screen. Clumps and feces are retained by the screen. Pivoting the lid to an open position dumps retained clumps and feces from the screen into the trash receptacle. While the lid is open, the held litter box containing unclumped sifted litter may be removed for use.