The ATLAS experiment at the CERN Large Hadron Collider (LHC) intensified its search for supersymmetry (SUSY) after the discovery of the Higgs boson in 2012. The search expanded in both breadth and depth, benefiting from higher collision energies and luminosity data collected between 2015 and 2018. This report summarizes the SUSY searches using 140 fb⁻¹ of pp collisions at 13 TeV, setting limits on the production of gluinos, squarks, and electroweakinos in various SUSY scenarios. The report covers a wide range of experimental signatures from both R-parity-conserving (RPC) and R-parity-violating (RPV) SUSY models. The paper introduces the main theoretical aspects of SUSY, the ATLAS detector, and the analysis strategy. It discusses the production of strongly and weakly produced SUSY particles, including gluino and squark pair production, slepton and electroweakino pair production, R-parity-violating decays, and long-lived SUSY particles. It also covers beyond simplified models and discusses the implications of the results for the SUSY landscape. The search for SUSY particles involves a variety of experimental signatures, including missing transverse momentum (pT^miss) from dark-matter candidates and long-lived particles. The analyses use simplified models to optimize the search and interpret results, but these models have limitations in generalizing to more complex SUSY scenarios. The results are interpreted in the Minimal Supersymmetric Standard Model (MSSM) to provide a broader picture of the SUSY landscape. The paper highlights the sensitivity of ATLAS to gluino masses up to 2 TeV and squark masses up to 1.8–1.9 TeV, with limits depending on the SUSY model parameters. The results are presented in various mass planes, showing exclusion limits for different SUSY scenarios. The analyses use a combination of data-driven techniques and Monte Carlo simulations to estimate backgrounds and set limits on SUSY particle masses and production cross-sections. The results provide important constraints on SUSY models and contribute to the ongoing search for new physics at the LHC.The ATLAS experiment at the CERN Large Hadron Collider (LHC) intensified its search for supersymmetry (SUSY) after the discovery of the Higgs boson in 2012. The search expanded in both breadth and depth, benefiting from higher collision energies and luminosity data collected between 2015 and 2018. This report summarizes the SUSY searches using 140 fb⁻¹ of pp collisions at 13 TeV, setting limits on the production of gluinos, squarks, and electroweakinos in various SUSY scenarios. The report covers a wide range of experimental signatures from both R-parity-conserving (RPC) and R-parity-violating (RPV) SUSY models. The paper introduces the main theoretical aspects of SUSY, the ATLAS detector, and the analysis strategy. It discusses the production of strongly and weakly produced SUSY particles, including gluino and squark pair production, slepton and electroweakino pair production, R-parity-violating decays, and long-lived SUSY particles. It also covers beyond simplified models and discusses the implications of the results for the SUSY landscape. The search for SUSY particles involves a variety of experimental signatures, including missing transverse momentum (pT^miss) from dark-matter candidates and long-lived particles. The analyses use simplified models to optimize the search and interpret results, but these models have limitations in generalizing to more complex SUSY scenarios. The results are interpreted in the Minimal Supersymmetric Standard Model (MSSM) to provide a broader picture of the SUSY landscape. The paper highlights the sensitivity of ATLAS to gluino masses up to 2 TeV and squark masses up to 1.8–1.9 TeV, with limits depending on the SUSY model parameters. The results are presented in various mass planes, showing exclusion limits for different SUSY scenarios. The analyses use a combination of data-driven techniques and Monte Carlo simulations to estimate backgrounds and set limits on SUSY particle masses and production cross-sections. The results provide important constraints on SUSY models and contribute to the ongoing search for new physics at the LHC.