We compute next-to-leading order QCD corrections to the top-bottom interference contribution to H+j production at the LHC. To achieve this, we combine the recent computation of the two-loop amplitudes for gg→Hg and qg→Hq, performed in the approximation of a small b-quark mass, and the numerical calculation of the squared one-loop amplitudes for gg→Hgg and qg→Hqg, performed within OpenLoops. We find that QCD corrections to the interference are large and similar to the QCD corrections to the top-mediated Higgs production cross section. We also observe a significant reduction in the mass-renormalization scheme uncertainty once the next-to-leading order QCD prediction for the interference is employed.