  Recent measurements in $B \to K^{(*)} \mu^+ \mu^-$ decays are somewhat
discrepant with Standard Model predictions. They may be harbingers of new
physics at an energy scale potentially accessible to direct discovery. We
estimate the sensitivity of future hadron colliders to the possible new
particles that may be responsible for the anomalies: leptoquarks or
$Z^\prime$s. We consider luminosity upgrades for a 14 TeV LHC, a 33 TeV LHC,
and a 100 TeV $pp$ collider such as the FCC-hh. Coverage of $Z^\prime$ models
is excellent: for narrow particles, with perturbative couplings that may
explain the $b$-decay results for $Z^\prime$ masses up to 20 TeV, a 33 TeV 1
ab$^{-1}$ LHC is expected to cover most of the parameter space up to 8 TeV in
mass, whereas the 100 TeV FCC-hh with 10 ab$^{-1}$ will cover all of it. A
smaller portion of the leptoquark parameter space is covered by future
colliders: for example, in a $\mu^+\mu^-jj$ di-leptoquark search, a 100 TeV 10
ab$^{-1}$ collider has a projected sensitivity up to leptoquark masses of 12
TeV (extendable to 21 TeV with a strong coupling for single leptoquark
production), whereas leptoquark masses up to 41 TeV may in principle explain
the anomalies.
