This work addresses the nonlinear control of a non-isothermal packed-bed reactor, modeled by two quasi-linear parabolic partial differential equations (PDEs). Initially, nonlinear Galerkin’s method and the concept of approximate inertial manifold are used to derive a minimal-order ordinary differential equation (ODE) model, which accurately describes the dynamics of the process. This model is then used for the synthesis of a nonlinear finite-dimensional controller that guarantees closed-loop stability and enforces output tracking. Computer simulations are used to evaluate the performance of the controller.