Abstract: The collapsible pet pen comprises a screen that may be deployed from within a cannister container and supported by a plurality of support poles. The cannister container and the screen may form a portable fence to confine a pet. Each of the plurality of support poles may comprise a pole body and a pole base. The pole base may be a ground base comprising a stake to push into the ground or a deck base that may be coupled to a deck or other flat surface. The cannister container and the leading edge of the screen may couple to a wall of a building using one or more wall coupler strips. The screen and the plurality of pole may couple to each other via a plurality of screen support fasteners dispersed at equal intervals along the screen and pole support fasteners found on each pole body.