  In this talk, I review the potential connection of neutrinos to the Physics
of the Early Universe, in particular the r\^ole of (sterile) neutrinos to
leptogenesis/baryogenesis and the dark sector of the Universe. The possibility
of CPT Violation among active neutrinos at early times and its role in
leptogenesis/baryogenesis without sterile neutrinos is also touched upon.
