Jet and Multijet Results from CMS

QCD measurements with jets are presented, from proton-proton collisions at a centre-of-mass energy of $7\,\mathrm{TeV}$ at the CERN LHC. The data were collected with the CMS detector during the 2010 data-taking period, and correspond up to an integrated luminosity of $36\,\mathrm{pb}^{-1}$. The measured inclusive-jet and dijet production cross sections are compared to perturbative QCD predictions at next-to-leading-order, and are found to be in good agreement. Observables sensitive to multijet production, such as the hadronic event shapes, the dijet azimuthal decorrelations, and the ratio of the 3-jet to 2-jet production cross section, are compared to the predictions of various QCD Monte-Carlo generators.