A Bluetooth audio that can be selectively installed on an umbrella shaft of an umbrella includes an audio body, a coupling shell and a clamp device. The audio body includes an installation recess which has an installation space for installing the umbrella shaft. The installation recess has a closed end corresponding to the substantial center of the audio body and an open end located on an edge of the audio body and corresponding to the closed end. The coupling shell can be selectively placed in the installation space through the open end and installed in the installation recess to close the open end and confine the umbrella shaft at the closed end. The clamp device is located in the audio body corresponding to the closed end and operable by a user's hand to clamp the umbrella shaft.