  We report a search for a magnetic monopole component of the cosmic-ray flux
in a 95-day exposure of the NOvA experiment's Far Detector, a 14 kt segmented
liquid scintillator detector designed primarily to observe GeV-scale electron
neutrinos. No events consistent with monopoles were observed, setting an upper
limit on the flux of $2\times 10^{-14} \mathrm{cm^{-2}s^{-1}sr^{-1}}$ at 90%
C.L. for monopole speed $6\times 10^{-4} < \beta < 5\times 10^{-3}$ and mass
greater than $5\times 10^{8}$ GeV. Because of NOvA's small overburden of 3
meters-water equivalent, this constraint covers a previously unexplored
low-mass region.
