Theoretical calculations for jet substructure observables with accuracy beyond leading-logarithm have recently become available. Such observables are significant not only for probing a new regime of QCD at hadron colliders, but also for improving the understanding
of jet substructure properties that are used in many searches for physics beyond the Standard Model. Some first measurements of such quantities are discussed. The soft drop mass is measured in dijet events with the ATLAS detector at $\sqrt{s}=$13 TeV and compared to Monte Carlo simulations and high accuracy fixed order calculations. A measurement of substructure variables in $t\bar{t}$ and inclusive jet events, using data collected by the ATLAS experiment at $\sqrt{s}=$13 TeV is also presented. The measurements are performed with large-radius jets. They are corrected for detector effects, represented as particle-level distributions and are compared to the predictions of various Monte Carlo event generators.