The influence of disorder on the temperature of the superconducting transition (Tc) is studied within the sigma-model renormalization group framework.  The electron-electron interaction in the particle-hole and Cooper channels is taken into account and assumed to be short-range.  Two-dimensional systems in the weak localization and antilocalization regime, as well as systems near the mobility edge are considered.  We show that in all these regimes Anderson localization leads to a strong enhancement of Tc, which is related to the multifractal character of wavefunctions.