This paper presents a new method to design an event-triggered dissipative observer-based control for discrete-time Takagi-Sugeno fuzzy singular systems by handling admissibility, dissipativity, observer-based control, and event-triggered data problems all in one. In particular, the proposed method has the advantage of being able to realize a one-step design framework that simultaneously designs both fuzzy observer and controller gains without using any iterative search algorithms. Furthermore, the proposed method provides the flexibility to set the fuzzy event weighting matrix in conjunction with other variables and supports the performance improvement of control systems by using a fuzzy Lyapunov function. Not only that, different from other eventtriggered output-feedback control techniques, the event generation function of this paper is constructed based on actual system outputs rather than estimated states so that estimation errors are not reflected in the event-triggered mechanism. Finally, two illustrative examples are given to verify the effectiveness of the proposed method.