We report on electro-optic beam deflection using an annealed proton exchange waveguide in lithium niobate (LN) with microstructured serrated array electrodes. Due to the electro-optic effect of the LN material, the experimental results show that the beam deflection and modulation of the LN waveguide can be realized with relatively low voltages. The total length of the serrated prism array electrodes structure is ∼5 mm. With 20 V applied to the electrodes of 50, 100, and 150 μm wide waveguides, ∼1.28, ∼0.96, and ∼0.64 μm beam deflections were obtained, respectively, which are in accordance with theoretical simulation. This configuration can be potentially applied in optical beam scanning, high-speed switches, and optical beam smoothing technology.