A tailgate outside handle assembly may include a housing installed in an outer panel of a tailgate, an actuator unit, a manipulating handle installed in the housing and having a manipulation portion in a front surface thereof, and a hinge shaft that may be coupled to a top end portion of a rear surface of the manipulation portion, wherein a bottom end portion of the manipulation portion may be engaged with the actuator unit and selectively rotated about the hinge shaft such that after the manipulation portion may be withdrawn to the outside of the housing by a driving force of the actuator unit when the tailgate may be to be opened, the manipulating handle works as a handle.