<p>This paper focuses on a novel guaranteed cost (GC) control method for discrete-time switched Takagi–Sugeno (T–S) fuzzy systems, where each subsystem is described by the T–S fuzzy model. Unlike traditional output feedback control strategies, the proposed method introduces past output measurements of the system as additional inputs to the controller, thereby providing more information for control decisions. This approach can improve the performance of the closed-loop system to some extent, particularly as the number of past outputs increases, leading to further performance enhancement. However, the introduction of past output measurements increases the computational dimension of the GC performance index, which presents challenges for the stability analysis of the system and the design of the controllers. The performance of the switched system is evaluated by the average dwell time (ADT) technique and the multiple Lyapunov functions (MLF). The controller design problem is then formulated as linear matrix inequality (LMI) constraints, and the controller gains are determined by solving the resulting LMI. The proposed method can improve the stability and performance of the system to a certain degree and can be applied to practical engineering systems such as stirred tank reactors and tunnel diode circuit systems, which can be modeled as switched T–S fuzzy systems. Finally, the effectiveness of the method is validated through two examples, demonstrating its advantages in practical applications.</p>