  We present the results of a search for heavy QCD axions performed by the
ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the
NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be
identified using the unique capabilities of ArgoNeuT and the MINOS near
detector. This decay channel is motivated by a broad class of heavy QCD axion
models that address the strong CP and axion quality problems with axion masses
above the dimuon threshold. We obtain new constraints at a 95\% confidence
level for heavy axions in the previously unexplored mass range between 0.2-0.9
GeV, for axion decay constants around tens of TeV.
