A measurement of charged-particle distributions sensitive to the properties of the
underlying event is presented for an inclusive sample of events containing a Z-boson,
decaying to a muon pair. The measurement is done using proton-proton collision data
collected by the ATLAS experiment at √s=13 TeV. Unfolded differential cross sections
are presented for charged particle multiplicity and charged particle transverse
momentum in regions of azimuth measured with respect to the Z-boson direction. The
data are compared to a wide variety of predictions from Monte Carlo event generators.