Abstract: The foldable stool has a triangular shaped seat with three upper legs attached to the corners of the seat. A leg holder is attached to the bottom portion of each upper leg. Lower legs are inserted into the leg holders. The foldable stool may also have additional leg segments that include a first lower engagement mechanism that is attached to the first lower leg. The first lower engagement mechanism protrudes radially outwardly from the first lower leg and is automatically movable between a lock position and a release position and insertable through the first opening of the first upper leg to lock the first upper leg to the first lower leg. The first lower engagement mechanism has a lower release surface upwardly protruding at a first acute angle relative to the first lower leg and an upper release surface so that the lower release surface and the upper release surface form a second acute angle.