An overview of the latest results on resonant and non-resonant Higgs boson pair production, using up to 140~fb$^{-1}$ of $\sqrt{s}=13$~TeV proton-proton collision data recorded during Run~2 of the LHC by the ATLAS and CMS Collaborations, is presented. A wide range of decay modes is covered, with one Higgs boson decaying to $b\bar{b}$, and the second to $b\bar{b}$, $W^+W^-$, $ZZ$, $\tau^+\tau^-$ or $\gamma\gamma$, as well as different topologies, with studies of both resolved and boosted signals and for both gluon-gluon and vector-boson fusion production modes. Analysis improvements, and newly introduced techniques with respect to previous studies, are highlighted.