Alexander Frank Wells (2 September 1912 – 28 November 1994), or A. F. Wells, was a British chemist and crystallographer. He is known for his work on structural inorganic chemistry, which includes the description and classification of structural motifs, such as the polyhedral coordination environments, in crystals obtained from X-ray crystallography. His work is summarized in a classic reference book, Structural inorganic chemistry, first appeared in 1945 and has since gone through five editions. In addition his work on crystal structures in terms of nets have been important and inspirational for the field of Metal-Organic Frameworks and related materials.