A search for supersymmetry in events with same-sign leptons and jets is presented. The analysis is performed with pp collision **data** collected at a centre-of-mass energy of √ s = 13 TeV between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 fb −1 . Five signal regions are defined to provide sensitivity to a broad range of supersymmetric processes. No significant excess over the yields expected from SM processes is observed, and model-independent limits on the cross-section of possible BSM signal contributions to the signal regions are reported.