This thesis presents a measurement of the neutrino oscillation parameters with the T2K experiment. A simultaneous analysis of ND280 and Super-Kamiokande data is performed to measure sin^2 θ_23, ∆m^2_32, sin^2 θ_13 and δ_CP. The parameters estimations performed in this thesis rely on a Bayesian statistical method sampling the parameters posterior probability distributions with a Markov chain Monte-Carlo technique. The analysed data correspond to an exposure of 7.482·10^20 protons on target (POT) in ν-mode and 7.471·10^20 in antiν-mode, consisting of the T2K runs 1 to 7. The mixing angle θ_13 is precisely measured in reactor experiments; using this external input the neutrino mixing parameters are measured to be sin^2 θ_23=0.51+0.04−0.05, ∆m^2_32=2.54+0.12−0.12·10^3 eV^2·c^−4,sin^2 θ_13=0.0219±0.0011, and δ_CP=−1.79+0.91−0.66 rad. CP-conservation in the neutrino sector is excluded with a 90% credibility (or C.L.). An analysis separating νμ from antiνμ disappearance finds consistent results between neutrino and antineutrino oscillations.