Stainless　steel　circular　hollow　section　(CHS)　members　have　been　widely　used　in　building　structures　because　of　their　comparable　strength　to　structural　carbon　steels,　attractive　appearance　and　excellent　corrosion　resistance.　However,　research　on　stainless　steel　CHS　members　has　been　limited　to　cold-formed　members,　whereas　hot　rolled　CHS　columns　have　received　less　attention.　To　this　end,　the　flexural　buckling　performance　of　hot-rolled　duplex　stainless　steel　CHS　columns　was　investigated　by　a　comprehensive　experimental　and　numerical　programme.　A　total　of　seven　hot-rolled　duplex　stainless　steel　CHS　columns　covering　two　cross-sectional　sizes　with　varying　lengths　have　been　tested　under　compression.　Based　on　the　test　results,　finite　element　(FE)　models　were　developed　and　used　in　parametric　studies　to　generate　data　points　with　a　wider　range　of　geometric　dimensions.　Comparing　the　test　and　FE　results　with　current　design　guidance,　it　was　found　that　the　Chinese　standard,　CECS　410,　and　North　American　design　guidance,　AISC　DG　27,　underestimate　significantly　the　flexural　buckling　resistance　of　such　columns,　while　the　design　method　in　Eurocode　3:　Part　1-4　might　be　unsafe　in　predicting　the　resistances　for　low　slenderness　values.　New　column　buckling　curves　based　on　the　Eurocode　3　and　AISC　DG　27　design　formulae　with　improved　accuracy　and　reduced　scatters　were　also　proposed　and　validated　through　careful　reliability　analysis.