  A measurement of the mass of the Higgs boson combining the $H\to ZZ^{*} \to
4\ell$ and $H\to\gamma\gamma$ decay channels is presented. The result is based
on 140 fb$^{-1}$ of proton-proton collision data collected by the ATLAS
detector during LHC Run 2 at a centre-of-mass energy of 13 TeV combined with
the Run 1 ATLAS mass measurement, yielding a Higgs boson mass of 125.11 $\pm$
0.09 (stat.) $\pm$ 0.06 (syst.) = 125.11 $\pm$ 0.11 GeV. This corresponds to a
0.09 % precision achieved on this fundamental parameter of the Standard Model
of particle physics.
