  In recent years the search for dark matter has intensified with competitive
bounds coming from collider searches, direct detection, and indirect detection.
Collider searches at the Large Hadron Collider (LHC) lack the necessary
center-of-mass energy to probe TeV-scale dark matter. It is TeV-scale dark
matter, however, that remains viable for many models of supersymmetry. In this
paper, we study the reach of a 100 TeV proton-proton collider for neutralino
dark matter and compare to 14 TeV LHC projections. We employ a supersymmetric
simplified model approach and present reach estimates from monojet searches,
soft lepton searches, and disappearing track searches. The searches are applied
to pure neutralino spectra, compressed neutralino spectra, and coannihilating
spectra. We find a factor of 4-5 improvement in mass reach in going from 14 TeV
to 100 TeV. More specifically, we find that given a 1% systematic uncertainty,
a 100 TeV collider could exclude winos up to 1.4 TeV and higgsinos up to 850
GeV in the monojet channel. Coannihilation scenarios with gluinos can be
excluded with neutralino masses of 6.2 TeV, with stops at 2.8 TeV, and with
squarks at 4.0 TeV. Using a soft lepton search, compressed spectra with a
chargino-neutralino splitting of $\Delta m = 20 - 30$ GeV can exclude
neutralinos at $\sim$ 1 TeV. Given a sufficiently long chargino lifetime, the
disappearing track search is very effective and we extrapolate current
experimental bounds to estimate that a $\sim$ 2 TeV wino could be discovered
and a $\sim$ 3 TeV wino could be excluded.
