The　behavior　of　fiber-reinforced　polymer　(FRP)-confined　recycled　aggregate　concrete-filled　steel　tube　(RACFT)　columns　is　barely　studied.　Especially,　that　of　slender　specimens　has　not　been　investigated　so　far.　In　this　article,　an　experimental　test　of　FRP-confined　RACFT　slender　square　columns　was　conducted　to　study　the　influences　of　recycled　aggregate　(RA)　replacement　ratios,　FRP　thicknesses,　and　wrapping　schemes　on　their　axial　behavior.　Results　in　this　article　suggest　that　the　RA　replacement　ratio　barely　affects　the　initial　stiffness　of　load-deflection　curves　of　specimens.　Moreover,　the　specimen　with　a　higher　RA　replacement　ratio　has　a　lower　axial　stress　but　larger　strain　at　the　peak　point.　The　external　FRP　jackets　(either　partial　or　full　wrap)　can　effectively　improve　the　performance　of　axially　loaded　RACFT　columns,　and　the　improvement　of　ductility　due　to　the　increase　of　the　FRP　thickness　is　more　significant　than　that　of　axial　compressive　strength.　Additionally,　it　was　found　that　the　axial　strength　and　ultimate　axial　strain　decrease　with　increasing　slenderness　ratios.　Furthermore,　the　influences　of　slenderness　ratios　on　the　behavior　of　such　columns　are　more　significant　for　the　column　with　a　larger　length-to-width　ratio.　Finally,　a　design　model　for　FRP-confined　RACFT　slender　square　columns　is　developed,　which　can　predict　the　results　of　the　present　test　accurately.