A measurement of the double-differential inclusive dijet production cross section in proton–proton collisions at is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 pb−1, recorded with the CMS detector at the LHC. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to y=2.5. It is found to be in good agreement with next-to-leading-order QCD predictions.