Optical coherence tomography (OCT) is a high-resolution microscopic optical imaging technique that yields real-time multi-dimensional images of subsurface tissue structure]. OCT is the optical analogue to ultrasound imaging but uses light waves instead of sound waves to create images. Near-infrared light enables micron-scale resolution, providing images on the same resolution scale as histopathology. OCT is based on a Michelson interferometer and, when combined with a sample scanning mechanism, forms cross-sectional images. Since its introduction in 1991 as a method for the non-invasive imaging of the retina, OCT has capitalized on technological advances, resulting in significant increases in data acquisition speeds, added functional modalities, and new contrast agents. OCT has been evaluated in a large number of clinical applications including ophthalmology, cardiovascular disease, and oncology, to name a few.