Abstract: The swing-away pet door apparatus, is adapted for mounting to the frame of a new or existing conventional sliding glass door assembly. A hinge member is secured to an elastomeric sealing flange, which is secured to the sliding glass door frame at a location adjacent to the sliding glass door. The hinge mounted to the elastomeric sealing flange positions the swing-away frame member between open and closed positions. In the open position, the swing-away frame member is positioned adjacent to the door frame and clear of the door frame tracks, providing substantially full access through the sliding glass door frame, when the sliding glass door is opened. The sliding glass door may also be completely closed and locked when the hinge member is in the open position.