The promising way to provide sufficient transmission capacity is by accessing transmission bands at higher carrier frequencies. This desire for higher carrier frequency or more bandwidth led the researchers to take advantage of the terahertz (THz) spectrum. The opportunity for large bandwidth in the THz band leads to the possibility of easy, high data rate transmission. In spite of the advantages, the THz band suffers from large free space path loss. In the development of THz communication systems, the antenna is the most significant component. The focus is especially on designing highly directive antennas because they enhance the performance of the overall system by compensating for the large path loss at THz and thus improving the signal-to-noise ratio. This chapter presents different types of THz antennas, including planar, reflectarray, horn antenna, and lens antenna. Emphasis has been made to present the latest trend of designing THz antennas using carbon-based materials, such as graphene and carbon nanotubes. The performance of these antennas has been compared with that of traditional copper-based THz antennas by critically analyzing their properties. A brief discussion on THz power sources is included in this chapter for completeness. A comprehensive discussion on different fabrication techniques has been provided to appraise the reader of the general fabrication processes of THz components.