This thesis concerns the development of a direct torque control strategy using a sliding mode control approach to optimize the power output of an oscillating water column (OWC) wave energy converter (WEC). The OWC WEC is a device that has a submerged vertical tail tube open at both ends, which is fixed to a floater that moves only in the heave direction. The ocean waves cause an oscillating motion of the air inside the tube, which drives a biradial turbine. To convert this mechanical energy into electrical energy, a doubly-fed induction generator (DFIG) was attached to the turbine. A direct torque control strategy using a sliding mode control approach was then developed to optimize the power output of the OWC WEC. The closed-loop stability of the SMC controller was proven through the Lyapunov stability theory. The control of the DFIG in irregular waves scenarios was investigated by means of tests run in the MATLAB/SIMULINK environment. The experimental results provided validation of the ability of the proposed sliding mode control algorithm to increase the power output of an OWC WEC device.