We measured two-neutrino double beta decay of $^{130}\mathrm{Te}$ using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: ${T}_{1/2}^{2\ensuremath{\nu}}={7.71}_{\ensuremath{-}0.06}^{+0.08}{(\mathrm{stat})}_{\ensuremath{-}0.15}^{+0.12}(\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{20}\text{ }\text{ }\mathrm{yr}$. This measurement is the most precise determination of the $^{130}\mathrm{Te}$ $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ decay half-life to date.
