The present invention provides a multipurpose connector for multiplexing a headset interface into a high-definition video/audio input interface and a handheld device including the multipurpose connector. The multipurpose connector includes a headset connector, a selecting switch, a high-definition video/audio transceiver, and an audio output module. The headset connector includes a first audio terminal and a second audio terminal. The audio output module is configured to output an audio signal of the headset. The selecting switch includes first and second lines. When the selecting switch communicates with the first line, the first audio terminal and the second audio terminal are coupled to a pair of differential transmission lines respectively, and the pair of differential transmission lines is configured to transmit high-definition video/audio data output by the high-definition video/audio transceiver. When the selecting switch communicates with the second line, the first audio terminal is coupled to the audio output module.