Measurements of the differential production cross sections $d\ensuremath{\sigma}/d{p}_{T}^{B}$ and $d\ensuremath{\sigma}/d{y}^{B}$ for ${B}^{0}$ mesons produced in $pp$ collisions at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$ are presented. The data set used was collected by the CMS experiment at the LHC and corresponds to an integrated luminosity of $40\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. The production cross section is measured from ${B}^{0}$ meson decays reconstructed in the exclusive final state $J/\ensuremath{\psi}{K}_{S}^{0}$, with the subsequent decays $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${K}_{S}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. The total cross section for ${p}_{T}^{B}g5\text{ }\text{ }\mathrm{GeV}$ and $|{y}^{B}|l2.2$ is measured to be $33.2\ifmmode\pm\else\textpm\fi{}2.5\ifmmode\pm\else\textpm\fi{}3.5\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$, where the first uncertainty is statistical and the second is systematic.
