Keratoconus is a chronic, non-inflammatory corneal disease, characterized by thinning of the corneal stroma and local corneal dilation with cone-shaped protrusion, and it usually leads to irregular astigmatism and myopia, posing great threat to eyesight. Corneal topography is the primary diagnostic tool for confirming keratoconus, while optical coherence tomography is now playing an increasingly important role in the diagnosis and treatment of keratoconus due to its ability of corneal sublayer imaging and superiority in repeatability, resolution, and data acquisition speed. This article discusses and reviews the clinical characteristics of keratoconus, the classification and characteristics of optical coherence tomography and its novel applications in the early diagnosis of keratoconus, contact lens fitting, corneal cross-linking therapy, and corneal transplantation; furthermore, progress in derivative technologies including optical coherence elastography, optical coherence tomography angiography, and polarization-sensitive optical coherence tomography associated with keratoconus is included in this article. We hope our study will help to further exploit the role of optical coherence technology in clinical keratoconus management.