Using the approach based on conformal symmetry we calculate the two-loop coefficient function for the vector flavor-nonsinglet contribution to deeply-virtual Compton scattering (DVCS). The analytic expression for the coefficient function in momentum fraction space is presented in the MS<mml:mo stretchy="true"><overbar></mml:mover> scheme. The corresponding next-to-next-to-leading order correction to the Compton form factor H for a simple model of the generalized parton distribution appears to be rather large: a factor two smaller than the next-to-leading order correction, approximately similar to 10% of the tree level result in the bulk of the kinematic range, for Q(2) = 4 GeV2.