A content delivery proxy system and method delivers content to an unsupported client device within a content delivery system by converting messages and data from the unsupported client device into content delivery system supported messages and data. Client log-in messages received from the unsupported client device are converted into a content delivery system supported format and sent to the content delivery system, and user entitlement information of a user of the unsupported client device is requested from the content delivery system. If the user is a subscriber of the content provider, an unsupported client device identifier is created for the client device. A user interface for selecting content from the content delivery system is displayed on the client device in a client device supported format, and selections on the user interface are sent to the content delivery system. Selected content is provided to the client device in the proper format for playback on the client device.