This paper deals with an <TEX>$H_{\infty}$</TEX> output feedback controller design for uncertain singularly perturbed T-S fuzzy systems. Integral quadratic constraints are used to describe various kinds of uncertainties of the plant. It is shown that the <TEX>$H_{\infty}$</TEX> norm of the uncertain singularly perturbed fuzzy system is less than <TEX>$\gamma$</TEX> for a sufficiently small <TEX>$\varepsilon$</TEX> > 0 if the <TEX>$H_{\infty}$</TEX> norms of both the slow and fast subsystem are less than <TEX>$\gamma$</TEX>. Using this fact, we develop a linear matrix inequality based design method which is independent of the singular perturbation parameter <TEX>$\varepsilon$</TEX>. A numerical example is provided to demonstrate the efficacy of the proposed design method.