  We derive new limits on light stops from diboson resonance searches in the
$\gamma\gamma$, $Z \gamma$, $ZZ$, $WW$ and $hh$ channels from the first run of
the LHC. If the two-body decays of the light stop are mildly suppressed or
kinematically forbidden, stoponium bound states will form in $pp$ collisions
and subsequently decay via the pair annihilation of the constituent stops to
diboson final states, yielding striking resonance signatures. Remarkably, we
find that stoponium searches are highly complementary to direct collider
searches and indirect probes of light stops such as Higgs coupling
measurements. Using an empirical quarkonia potential model and including the
first two $S$-wave stoponium states, we find that in the decoupling limit
$m_{\widetilde t_1} \lesssim 130$ GeV is excluded for any value of the stop
mixing angle and heavy stop mass by the combination of the latest resonance
searches and the indirect constraints. The $\gamma \gamma$ searches are the
most complementary to the indirect constraints, probing the stop "blind spot"
parameter region in which the $h^0 \tilde t_1 \tilde t_1^*$ trilinear coupling
is small. Interestingly, we also find that the $Z\gamma$ searches give a
stronger constraint, $m_{\widetilde t_1} \lesssim 170$ GeV, if the stop is
primarily left-handed. For a scenario with a bino LSP and stop NLSP, several
gaps in the direct collider searches for stops can unambiguously be filled with
the next run of the LHC. For a stop LSP decaying through an R-parity violating
$UDD$ coupling, the stoponium searches can fill the gap 100 GeV $\lesssim
m_{\tilde t_1} \lesssim 200$ GeV in the direct searches for couplings $\lambda"
\lesssim 10^{-2}$.
