When Galileo designed the tube of his first telescope, optomechanics was born. Concerned with the shape and position of surfaces in an optical system, optomechanics is a subfield of physics that is arguably as old as optics. However, while universities offer courses on the subject, there is a scarcity in textbook selections that skillfully and properly convey optomechanical fundamentals to aspiring engineers. Complemented by tutorial examples and exercises, this textbook rectifies this issue by providing instructors and departments with a better choice for transmitting to students the basic principles of optomechanics and allowing them to comfortably gain familiarity with the field's content. Practicing optical engineers who engage in self-study and wish to enhance the extent of their knowledge will also find benefit from the vast experience of the authors. The book begins with a discussion of materials based on optomechanical figures of merit and features chapters on windows, prisms, and lenses. The authors also cover topics related to design parameter, mounting small mirrors, metal mirrors with a discussion of infrared applications, and kinematic design. Overall, Fundamentals of Optomechanics outfits students and practitioners with a stellar foundation for exploring the design and support of optical system surfaces under a wide variety of conditions.