An outdoor umbrella includes an awning, an umbrella frame, an illumination system, a power supplying system, a solar energy supplying system, and a powering control circuit. The power supplying system includes a rechargeable battery supported by the umbrella frame and is electrically connected with the illumination system for supplying electrical power to the illumination system. The solar energy supplying system includes a solar energy collection unit for collecting solar energy, and a solar battery unit. The powering control circuit electrically connects the solar battery unit with the rechargeable battery to coordinate a power supply to the illumination system, wherein the powering control circuit selectively switches the power supply of the illumination system between the power supplying system and the solar energy supplying system for ensuring the illumination system obtaining sufficient power to provide optimal level of illumination.