Abstract: A toilet anti-overflow device for preventing a toilet bowl from overflowing by a flapper that is stuck in an open position over a flush valve seat. The toilet anti-overflow device includes a toilet with a toilet bowl and a water tank in fluid communication with the toilet bowl. The water tank has a flush valve seat therein and an overflow tube upwardly extending from the flush valve seat. The water tank has a flexible flapper pivotally coupled to the overflow tube and covering the flush valve seat. A collar is slidably disposed around overflow tube. One end of an elongate flexible cable is coupled to the collar. The other end of the cable is wrapped around a spool coupled to a rotating shaft of a motor. A controller is electrically connected to the motor to selectively energize the motor to selectively rotate the rotating shaft. A switch is provided in the toilet bowl and is electrically connected to the controller.