A pet vestibule configured for being attached to a door and to either swing open with the door or to be removably installed so the vestibule can be released from the interior side of the door before the door is opened, and the door can swing freely. The vestibule can then be rolled out of the doorway. The vestibule provides a protected shelter area for pets and animals to come and go into a structure without the need for human assistance, while also inhibiting rain, snow, and other inclement weather from entering the structure through the pet door.
