This　paper　presents　a　new　metallic　damper　called　hexagonal　honeycomb　steel　damper　(HHSD)　for　damage　mitigation　in　structures　subjected　to　earthquake　excitations.　The　HHSD　is　composed　of　steel　plates　having　several　hexagonal　and　welded　to　the　top　and　bottom　anchor　plates.　The　damper　takes　the　advantages　of　hexagonal　honeycomb　geometry　and　steel　material　capability　to　dissipate　seismic　energy.　The　quasi-static　cyclic　test　was　performed　experimentally　and　numerically　on　a　series　of　specimens　to　evaluate　the　robustness　of　the　HHSD.　A　three-dimensional　finite　element　analysis　of　HHSD　was　carried　out　and　verified　with　the　experimental　results.　The　results　showed　that　the　HHSD　has　low　yield　displacement,　stable　hysteretic　behavior,　a　good　range　of　ductility　and　high-energy　dissipation　capability.　Additionally,　the　constitutive　formulas　of　the　damper　are　also　derived　based　on　the　obtained　results.　Furthermore,　it　is　found　to　have　lightweight　and　inexpensive　with　ease　of　implementation　as　a　potential　alternative　for　new　structures　or　seismic　retrofitting　of　the　existing　structures.　©　2020,　Wroclaw　University　of　Science　and　Technology.