The measurement of Higgs boson production in association with a $t\bar{t}$ pair ($t\bar{t}H$) is essential to understand the top-quark couplings to the Higgs boson: it allows for a direct measurement of the top Yukawa coupling and completes the indirect measurement based on the production of the Higgs boson in gluon-gluon fusion and in the decay of the Higgs boson to pair of photons. These proceedings present the results of the recent $t\bar{t}H$ analyses using up to 139 fb$^{-1}$ of $pp$ collision data collected at a center-of-mass energy of $\sqrt{s}$ = 13 TeV by the ATLAS detector at the Large Hadron Collider. The results of the searches in different Higgs boson decay channels are presented.
The combination of the results is also presented. It uses up to 79.8~fb$^{-1}$ of data recorded at $\sqrt{s}$ = 13 TeV in combination with searches performed at $\sqrt{s}$ = 7 TeV and 8 TeV, corresponding to an additional 4.9 fb$^{-1}$ and 20.8 fb$^{-1}$ integrated luminosity of $pp$ collision data, respectively. The production of the Higgs boson in association with a top quark pair is observed with a significance of 6.3 standard deviations relative to the background-only hypothesis. The expected significance is 5.1 standard deviations.