The dynamics of the excess proton in water/methanol mixtures (1:9) is studied using two-dimensional infrared (2D IR) spectroscopy techniques. The experimental data are analyzed using global fitting methods. The resulting two-dimensional spectra consist of two contributions, one from water and one from methanol. For the water contribution, the spectral diffusion is slower in the mixture compared to pure water, and a red-shift of the central line suggests enhanced H-bond strength. The dynamics of the proton exchange between water and methanol is characterized by a time constant of about 1.2 ps, which is significantly longer than the proton transfer time in pure methanol (about 0.5 ps). This result is consistent with lower acidity of water compared to methanol. The 2D IR spectra also show a weak but distinguishable contribution of an excited-state overtone transition indicating that the proton transfer reaction leads to significant changes of the structure and vibrational frequencies of the transient intermediates.