Searches for additional Higgs bosons at ATLAS

The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable to solely explain some observations. Many extensions addressing such shortcomings introduce additional Higgs-like bosons which can be either neutral, singly-charged or even doubly-charged, or additional resonances with masses larger or smaller than that of the Standard Model Higgs boson. The current status of searches for these particles based on the full LHC Run 2 dataset of the ATLAS experiment at 13 TeV are presented.