  We discuss JUNO sensitivity to the annihilation of MeV dark matter in the
galactic halo via detecting inverse beta decay reactions of electron
anti-neutrinos resulting from the annihilation. We study possible backgrounds
to the signature, including the reactor neutrinos, diffuse supernova neutrino
background, charged- and neutral-current interactions of atmospheric neutrinos,
backgrounds from muon-induced fast neutrons and cosmogenic isotopes. A fiducial
volume cut, as well as the pulse shape discrimination and the muon veto are
applied to suppress the above backgrounds. It is shown that JUNO sensitivity to
the thermally averaged dark matter annihilation rate in 10 years of exposure
would be significantly better than the present-day best limit set by
Super-Kamiokande and would be comparable to that expected by Hyper-Kamiokande.
