Leptonic Charm Decays

We review the recent experimental results on D and Ds meson leptonic decays from CLEO-c, Belle, and BABAR, which results in the decay constants f_D= (206.7 ± 8.9) MeV and f_Ds= (257.3 ± 5.3) MeV. The latter is an average obtained by the Heavy Flavor Averaging Group (HFAG). Comparisons with Lattice QCD (LQCD) calculations are discussed.