With the proton-proton collision data collected during 2015 and 2016 at the centre-of-mass energy of 13 TeV, the ATLAS experiment is exceeding the sensitivity reached with the
analysis of the 7 and 8 TeV data during LHC Run 1 for many New Physics scenarios involving top quarks and their heavy partners. In this contribution, some of the latest ATLAS results in searching for top-pair resonances, top and bottom vector-like quarks and four-top-quark events are shortly reviewed
