  We propose a Majorana fermion dark matter in the context of a simple
gauge-Higgs Unification (GHU) scenario based on the gauge group $SU(3)$ x
$U(1)'$ in 5-dimensional Minkowski space with a compactification of the 5th
dimension on $S^1/Z_2$ orbifold. The dark matter particle is identified with
the lightest mode in $SU(3)$ triplet fermions additionally introduced in the
5-dimensional bulk. We find an allowed parameter region for the dark matter
mass around a half of the Standard Model Higgs boson mass, which is consistent
with the observed dark matter density and the constraint from the LUX 2016
result for the direct dark matter search. The entire allowed region will be
covered by, for example, the LUX-ZEPLIN dark matter experiment in the near
future. We also show that in the presence of the bulk $SU(3)$ triplet fermions
the 125 GeV Higgs boson mass is reproduced through the renormalization group
evolution of Higgs quartic coupling with the compactification scale of around
$10^8$ GeV.
