The list presents electron collision strengths for the forbidden transitions between the fifteen lowest levels of the doubly-ionized cobalt, Co^2+^, as a function of the electron energy, in an intermediate coupling scheme using the Breit-Pauli relativistic terms as implemented in an R-matrix atomic scattering code. An atomic target for the R-matrix scattering defined by 36 atomic terms is used in these calculations. The data are particularly useful for analyzing the thermodynamic conditions of supernova ejecta.