Lonnie Royce (Lon. R.) Shelby (August 2, 1935 - April 8, 2018) was an American academic, and Professor Emeritus of Speech Communication and former Dean of the College of Liberal Arts at the Southern Illinois University. He is known for his work on Mediaeval architects and design, especially on the work of Lorenz Lechler, Mathes Roriczer, Hanns Schmuttermayer, Taccola and Villard de Honnecourt. He is also known for coining the term constructive geometry.