  We present a strong coupling constant extraction at Next-to-Leading Order QCD
accuracy using ATLAS Z+2,3,4 jets data. This is the first extraction using
processes with a dependency to high powers of the coupling constant. We obtain
values of the strong coupling constant at the $Z$ mass compatible with the
world average and with uncertainties commensurate with other NLO extractions at
hadron colliders. Our most conservative result for the strong coupling constant
is $\alpha_S=0.1178 ^{+0.0051}_{- 0.0043}$.
