This　study　bridges　the　knowledge　gap　regarding　the　eccentric　compression　behavior　of　circular　ultra-high-strength　concrete　filled　high-strength　steel　tube　(CuFShT)　columns.　Tests　on　12　medium-length　CuFShT　specimens　with　varying　steel　contents　and　load　eccentricities　revealed　their　failure　modes,　load-deflection　responses,　and　steel　strains.　Finite　element　models　were　developed　to　analyze　the　effects　of　load　eccentricity,　slenderness　ratio,　and　cross-sectional　parameters　on　the　ultimate　load-bearing　capacity.　Calculation　methods　for　the　ultimate　capacity,　including　an　evaluation　of　existing　design　codes,　are　discussed,　and　an　explicit　method　for　engineering　applications　is　proposed.　The　results　show　that　an　increased　steel　content　enhances　the　flexural　stiffness　and　load-bearing　capacity,　whereas　a　higher　eccentricity　significantly　reduces　the　load-bearing　capacity.　The　combined　influence　of　the　eccentricity　and　slenderness　ratio　suggests　the　need　for　an　overall　reduction　factor　in　the　design　calculations.　After　normalizing　the　slenderness,　the　cross-sectional　parameters　showed　a　minimal　impact.　Among　the　existing　design　codes,　including　AISC　360–16,　AIJ-2008,　and　T/CECS　987–2021,　the　European　standard　EN　1994–1–1　provides　the　most　accurate　predictions　for　CuFShT　columns.　By　incorporating　the　Perry-Robertson　formula,　the　coupled　effects　of　the　eccentricity　and　slenderness　ratio　were　effectively　captured,　enabling　a　precise　estimation　of　the　ultimate　load-bearing　capacity　for　eccentrically-compressed　CuFShT　columns　using　the　explicit　calculation　formula.　©　2025　The　Authors