Abstract: A collapsible pet travel crate for use with at least one car seat includes an internal frame and a housing. The internal frame has two side members and four foldable members extending between the side members. Each side member has an upright rear portion. Each foldable members a first piece and a second piece coupled to the first piece through a lockable hinge. Each first piece is coupled to one side member through a first pivot hinge. Each second piece is coupled to the other side member through a second pivot hinge. The housing includes two oppositely disposed side panels and a central panel. Each side panel also has an upper mounting slot and a lower mounting slot. The housing includes a front mounting strap. The car seat belt extends through the first and second slots and across the front surface of the rear portions of the two side members.