  We compute the next-to-leading order (NLO) QCD corrections to the
gluon-fusion subprocess of diphoton-plus-jet production at the LHC. We compute
fully differential distributions by combining two-loop virtual corrections with
one-loop real radiation using antenna subtraction to cancel infrared
divergences. We observe significant corrections at NLO which demonstrate the
importance of combining these corrections with the quark-induced
diphoton-plus-jet channel at next-to-next-to-leading order (NNLO).
