We experimentally demonstrate three-fold wavelength multicasting of a 64-quadrature-amplitude-modulation (QAM), 120-Gbit/s data channel using a microresonator Kerr frequency comb and nonlinear wave mixing. The multicasting is achieved with a data signal and four comb lines serving as the pump lasers in a periodically poled lithium niobate (PPLN) waveguide. Minimal extra phase noise from the pumps is introduced into the multicast copies due to the mutual coherence between the Kerr comb lines. All three multicast copies achieve a bit-error rate (BER) <= 3.5E-3, which is below the forward-error-correction threshold. Both the error vector magnitude (EVM) and BER performances show <0.5-dB optical signal-to-noise ratio (OSNR) penalty for the multicast copies compared to the original data signal.