Tokamaks are toroidal devices in which a plasma is confined by means of helical magnetic fields with the purpose of obtaining energy from nuclear fusion reactions. The safety factor, q, measures the pitch of the helical magnetic field lines in a tokamak. Active control of the q profile (i.e., spatial shape) is needed due to its relationship with plasma performance, steady-state operation, and magneto-hydrodynamic stability. However, the responses of some plasma magnitudes, such as the electron temperature, are difficult to model and introduce a high level of uncertainty in the model used for q-profile control design. Control algorithms that are robust against such model uncertainties must be developed in order to ensure successful q-profile regulation. In this work, a nonlinear, robust q-profile controller is designed using feedback linearization and nonlinear damping techniques. The controller makes use of plasma current modulation, neutral beam injection, electron-cyclotron heating & current drive, and electron density modulation as actuation methods. A simulation study is carried out for a DIII-D scenario to test the controller's performance under the presence of electron temperature uncertainties.