Following the discovery of a scalar particle in 2012, with a mass of 125 GeV and properties compatible with the Standard Model Higgs boson, an extensive search program for additional neutral and charged Higgs bosons is on-going at the Large Hadron Collider, in particular with the ATLAS experiment. This seminar will provide a review of the results obtained with the pp collision data recorded by ATLAS in 2015 and 2016. Constraints on new physics with an extended Higgs sector will also be discussed.