The UV/Optical Telescope (UVOT) is one of the three instruments aboard the Swift Gamma-ray Observatory, designed to capture early UV and optical photons from gamma-ray burst (GRB) afterglows in the 170-600 nm band. The UVOT uses a modified Ritchey-Chrétien design with micro-channel plate intensified charged-coupled device detectors, capable of recording the arrival time of individual photons and providing sub-arcsecond positioning of sources. The instrument includes a 30 cm primary mirror, an f-number of 12.7, and two redundant detectors each with an 11-position filter wheel. The filter wheels accommodate UV/optical grisms, broadband color filters, a 4x magnifier, a clear "white-light" filter, and a blocking filter. The UVOT's design and operation are detailed, including its mechanical, optical, and electronic components, as well as its thermal and software systems. The UVOT's capabilities and scientific goals are discussed, highlighting its role in studying GRBs and their afterglows.The UV/Optical Telescope (UVOT) is one of the three instruments aboard the Swift Gamma-ray Observatory, designed to capture early UV and optical photons from gamma-ray burst (GRB) afterglows in the 170-600 nm band. The UVOT uses a modified Ritchey-Chrétien design with micro-channel plate intensified charged-coupled device detectors, capable of recording the arrival time of individual photons and providing sub-arcsecond positioning of sources. The instrument includes a 30 cm primary mirror, an f-number of 12.7, and two redundant detectors each with an 11-position filter wheel. The filter wheels accommodate UV/optical grisms, broadband color filters, a 4x magnifier, a clear "white-light" filter, and a blocking filter. The UVOT's design and operation are detailed, including its mechanical, optical, and electronic components, as well as its thermal and software systems. The UVOT's capabilities and scientific goals are discussed, highlighting its role in studying GRBs and their afterglows.