Terahertz (THz) metasurface antennas are currently at the forefront of advanced research and technological innovation due to their unique ability to manipulate electromagnetic waves in the THz frequency range. These antennas have garnered considerable attention due to their potential applications in various domains, including communication, imaging, sensing, and beyond. This chapter explores the fascinating realm of metasurface antennas operating in the THz frequency range, an emerging frontier in electromagnetic wave technology. The band holds immense promise for a wide range of applications, from advanced communication systems to high-resolution imaging and spectroscopy. Metasurface antennas, leveraging their unique capabilities, have shown exceptional potential in harnessing and manipulating THz waves. The chapter begins by providing a comprehensive overview of the THz spectrum and its significance in contemporary technology. It highlights the challenges and opportunities associated with THz frequencies, emphasizing the significance of metasurfaces in facilitating the development of THz antennas. Fundamental principles governing metasurface antennas are discussed, with a particular focus on their adaptability to THz waves. The ability to precisely control the phase and polarization of THz radiation is explored in detail, showcasing the important role of metasurfaces in achieving efficient THz beamforming and steering. Design methodologies for metasurface antennas operating in the THz regime are examined, encompassing unit cell optimization, phase gradient control, and impedance matching. The chapter emphasizes the significance of material selection and fabrication techniques tailored to THz frequencies. The chapter provides an overview of the potential impact of THz metasurface antennas on many domains, highlighting their ability to bring about significant advancements. These antennas provide remarkable characteristics such as ultrahigh data rates and accurate molecule sensing, which have the potential to revolutionize these fields. In conclusion, this particular chapter of the book offers a comprehensive exploration of metasurface antennas that operates in the Terahertz frequency range. It serves as a valuable resource for researchers, engineers, and students seeking to understand the pivotal role of metasurfaces in unlocking the potential of THz technology.