The reproduction of surface waves within hydraulic laboratories or numerical simulations is crucial when attempting to understand how different types of coastal andoffshore structures perform under various sea states. These waves are usually produced within a wave flume via the forward and backward motion of a pistonwavemaker. By controlling the translational motion of these physical or numerical wavemakers, regular waves with a constant wave height and wavelength, orirregular waves corresponding to different wave spectra, can be created. Such waves can then be used to study the behavior of structures placed within the flume thatmay be susceptible to similar wave conditions in the field. This chapter will introduce the methods by which different types of waves can be generated.