A toilet overflow prevention assembly for capturing overflowing water from a toilet includes a collar that is comprised of a flexible material. The collar can be positionable around a bowl of a toilet thereby facilitating the collar to capture water overflowing from the bowl. Additionally, the collar is comprised of a fluid impermeable material to inhibit the water from passing therethrough. A drain is integrated into the collar to drain the water outwardly therefrom. A closure is hingedly coupled to the collar and the closure is positionable in a locked position when the collar is positioned in the closed position for retaining the collar in the closed position.