This　paper　studies　the　axial　compressive　behavior　of　square　timber　filled　steel　tube　(TFST)　stub　columns.　A　total　of　twelve　specimens,　including　bare　timber　columns,　hollow　steel　tube　columns,　and　TFST　columns,　are　fabricated　and　tested.　Test　variables　include　the　number　of　confining　carbon　fiber　reinforced　plastics　(CFRP)　layers　and　the　timber　condition　(with　or　without　knots).　The　failure　modes,　load　versus　deformation　relationships,　strain　characteristics,　ultimate　strength,　ductility,　stiffness,　and　strength-to-weight　performance　are　investigated.　The　confining　effect　of　CFRP　on　TFST　columns　is　also　analyzed.　Test　results　show　that　the　TFST　columns　have　higher　strength　and　ductility　compared　with　the　hollow　steel　tube　columns　or　the　bare　timber　columns.　The　presence　of　knots　reduces　column　strength　and　ductility.　CFRP　can　increase　the　axial　compressive　strength　of　columns.　TFST　columns　have　good　strength-to-weight　performance,　indicating　that　high　strength　values　can　be　achieved　using　light　TFST　columns.