  We present a measurement of $\eta$ production from neutrino interactions on
argon with the MicroBooNE detector. The modeling of resonant neutrino
interactions on argon is a critical aspect of the neutrino oscillation physics
program being carried out by the DUNE and Short Baseline Neutrino programs.
$\eta$ production in neutrino interactions provides a powerful new probe of
resonant interactions, complementary to pion channels, and is particularly
suited to the study of higher-order resonances beyond the $\Delta(1232)$. We
measure a flux-integrated cross section for neutrino-induced $\eta$ production
on argon of $3.22 \pm 0.84 \; \textrm{(stat.)} \pm 0.86 \; \textrm{(syst.)}$
$10^{-41}{\textrm{cm}}^{2}$/nucleon. By demonstrating the successful
reconstruction of the two photons resulting from $\eta$ production, this
analysis enables a novel calibration technique for electromagnetic showers in
GeV accelerator neutrino experiments.
