The work deals with the design of functional observers for systems described by Takagi-Sugeno (T-S) fuzzy models with time delay constant time delay and varying time delay. Two design methods are proposed. The design conditions for a fuzzy functional observer are presented in terms of LMI constraints. The proposed approach has been evaluated using the Yalmip/MATLAB toolbox and Simulink/MATLAB software. Finally, two numerical examples are given to show the feasibility of the proposed approaches.