  We study the Gauss-Bonnet (GB) holographic superconductors in the presence of
an external magnetic field. We describe the phenomena away from the probe
limit. We derive the critical magnetic field of the GB holographic
superconductors with backreaction. Our analytical approach matches the
numerical calculations. We calculate the backreaction corrections up to first
order of $O(\kappa^2=8\pi G)$ to the critical temperature $T_C$ and the
critical magnetic field $B_C$ for a GB superconductor. We show that the GB
coupling $\alpha$ makes the condensation weaker but the backreaction
corrections $O(\kappa^2)$ make the critical magnetic field stronger.
