The elastic properties of copper have been compiled and reviewed. Polycrystalline elastic constants included are: Young's modulus, the shear mociululO, the bulk modulm, and PoislOon's ratio. Single·crystal constantlO of second·, third., and fourth·order are included. Over 200 refer· ences to the experimental literature are given. A few theoretical numbers are included. When suffieient data exist, hest values are recommended together with their standard errors. Effects on the elastic constants of tf'mperature, pressure, and mechanical (plastic) deformation are in· cluded. The Cauchy (central·force) relationships and the single·crystal-polycrystal relationship are also discussed.