Elisha King Root (May 5, 1808 - September 1, 1865) was a Connecticut machinist, inventor, and President of Colt's Manufacturing Company. Root was born on a Massachusetts farm and worked as a bobbin boy in a cotton mill before switching, at the age of 15, to working in a machine shop in Ware, Massachusetts. At age 24 he was hired by Connecticut industrialist Samuel W. Collins to work in his axe factory in Collinsville, a village of Canton, Connecticut. After Colt's death in 1862, Root took over as president of Colt's Patent Firearms until his death on September 1, 1865.