The present utility model provides an integrated fully enclosed cat lavatory comprising a cat lavatory body and a cat litter pan, wherein: the cat lavatory body is hexahedral, the cat lavatory body has an open underside, the shape of the cat litter pan and that of the open underside of the cat lavatory body are adaptable to each other, the top and two sides of the cat lavatory body are curved, the front of the cat lavatory body is provided with a circular opening for a cat to get in and out, a cat litter footboard extending into the cat lavatory body is provided at the bottom of the circular opening, engagement slots are disposed beneath the circular opening for the cat litter pan to be engaged therewith, the cat litter pan is slid to be placed into the cat lavatory body to enclose the open underside of the cat lavatory body. The present utility model is structurally simple, integrally formed and easy to clean.