Particle production at LHC energies involves perturbative (hard) and
non-perturbative (soft) QCD regimes. At low transverse momentum it is generally described by phenomenological models. In this contribution, we report on soft QCD variables, such as inelastic, single- and double-diffractive cross sections, charged-particle multiplicity density and observables characterising the Underlying Event. Results are presented for data from pp, p--Pb, Xe--Xe and Pb--Pb collisions at LHC energies
reconstructed with the ALICE detector. The evolution of particle production with energy and system size is discussed.